RSMCGUITAR
Not true. They don't all use the same driver and my 2i4 is not compatible with mixcontrol

Cactus Music
The solo, 2i2 and 2i4 do not come with Mix Control.  And the drivers are different for each model.  The numbers are not even close.  I think the 6i6 and upward share a driver and the mix control this is not clear when you look at the download pages.  All it says is Mixcontrol 1.8 contains all the drivers you will need.    

Ugh... wrong.  Not sure why we are arguing about this but, like I said before, MixControl bundles the USB driver.  If your interface doesn't support MixControl, then you just get the unbundled USB driver.  Go to the Focusrite page and run the installer for MixControl 1.8 from the download page for any 1st gen device that supports it.  You'll see that it pops up the installer for USB driver version 2.5.1.  Now go to the download page for any non-MixControl 1st gen device and what do you see?  USB driver version 2.5.1.  
 
It's even clearer on the beta site where the release notes for the USB drivers will list fixes/features that apply across the full model range plus a couple of changes that apply only to specific models across the range.  To add some confusion, they have released versions of the beta drivers that apply only to specific models but these are still the same driver.  They just have changes not applicable across the range (and they presumably don't want to regression test against the entire range of hardware so they tell you not to install it if you don't have that device and specific problem).  
 
But in any case, I do think we agree that the 1st gen is probably worth avoiding.

I apologize Dave, on further inspection you seem to be correct. I guess I was hung up with how it said this on the beta page:
This driver is for Scarlett Solo/2i2/2i4 only! Do not install this is you have a 1st Generation Scarlett 6i6/18i8/18i20 

As an aside, it would seem that the beta page was just updated this afternoon with what appears to be a new version of the Control software.

So there is a Beta page how are we supposed to know that Iève always just checked the Focusrite site like a good boy and that is that. So you folks are saying there is a new version of Mix Control and it works with 1st Gen interfaces. 
My keyboard is typing weird letters right now.. a question mark = É  

RSMCGUITAR
I apologize Dave, on further inspection you seem to be correct. I guess I was hung up with how it said this on the beta page:
This driver is for Scarlett Solo/2i2/2i4 only! Do not install this is you have a 1st Generation Scarlett 6i6/18i8/18i20

 
No worries.  I only know this stuff because I've had both the 2i4 and 18i20 (and helped a band mate with his 6i6) and because of all I've gone through with installing/reverting all sorts of driver versions to try to resolve the stability issues I've had.  That warning definitely adds to the confusion.  My interpretation is that it's still the same driver across the line (because you wouldn't need the warning about installing it with the 6i6+ otherwise) but they've updated it in some way that is incompatible with the 6i6+ models.  
 
This kind of confusion with the drivers and what devices they apply to, etc. is a big part of my frustration with the 1st gen hardware.  I don't have experience with the 2nd gen but get the impression that there is much less crossing your fingers while installing beta drivers involved.  
 

Cactus Music
So there is a Beta page how are we supposed to know that Iève always just checked the Focusrite site like a good boy and that is that. So you folks are saying there is a new version of Mix Control and it works with 1st Gen interfaces. 
 

Here's the beta page: http://beta.focusrite.com/  
 
Be VERY cautious about installing any of these if your hardware is working perfectly for you.  On some of these, you can't roll back the firmware so you are stuck with the latest version of the driver and MixControl even if you don't like it.

I thought that I'd report back to let you know what I ended up doing.
I managed to get hold of a 1st gen 6i6 to try - and compared to my old Tascam interface the latency was much better and it seems to function well. I'm mainly using VST instruments with a few audio tracks and working with external pre-amps for the mics. I've messed around with it over the weekend and I'm happy that it will meet my needs, and with the limted testing that I've done the drivers (just the official release, I've not tried the newer beta) seem to be pretty stable.
Given the low price for the clearance models direct from Focusrite (£109) it's going to be fine for me - sure there are better models out there, but this is such an improvement over my old interface that I'm very pleased with the results.
 
 
Alistair C.
 
 

That's great, I certainly don't have driver issues with mine and as you said you have outboard pre amps that solves my only gripe, the touchy pre amps.  Overall I'm super happy with the design. Nice metal case, solid and portable. The big knob for levels, 2 headphones and  exactly the right connectivity for my set up. 
 
I would be curious to compare Round trip latency between the old and new models. Bet the improvement is marginal. 
And I'd also like to try the new pre amps and see if they resolved that issue. 
But, I'm not replacing mine anytime soon and when I do it will most likely be a Motu or RME. 
 
Thanks for the link Dave. Ya, I won't be trying anything new. Mine is rock solid on 3 different systems. 

I'll just add that if you buy the first generation 2i4 for £85 delivered, you can use the second-generation drivers (only 2i4 and below can do this), it is bus powered and you get the full software bundle (including Addictive Keys) and are eligible for the Plug-in collective.
 
It is the best £85 I've ever spent and I continue to receive more goodies!
 
So far, I've received:
 
- The stable, low-latency interface itself
- Addictive Keys Studio Grand
- Exponential Audio R2 reverb
- Syntorus double path analogue chorus
- Flux Studio Session Analyzer
- Positive Grid BIAS FX LE
- Sound Radix SurferEQ 2 Boogie
- Eventide 2016 Stereo Room
- iZotope DDLY Dynamic Delay
- BIAS Amp LE
- Ableton Live Lite
- Scarlett Plugin Suite
- Novation Bass Station
- Free Loopmasters Content
- Red Plugin Suite
- Softube Time and Tone bundle
- Focusrite Drum Tracks
- Focusrite 2016 Loopmasters Content
 
There are also other options for discounted upgrades, the best of which is Softube Time and Tone Plus upgrade which contains Fix Flanger and Doubler, Amp Room Essentials and the FET Compressor which you can pick up for $84 to upgrade the Time and Tone bundle. 

alistairc
I thought that I'd report back to let you know what I ended up doing.
I managed to get hold of a 1st gen 6i6 to try - and compared to my old Tascam interface the latency was much better and it seems to function well. I'm mainly using VST instruments with a few audio tracks and working with external pre-amps for the mics. I've messed around with it over the weekend and I'm happy that it will meet my needs, and with the limted testing that I've done the drivers (just the official release, I've not tried the newer beta) seem to be pretty stable.
Given the low price for the clearance models direct from Focusrite (£109) it's going to be fine for me - sure there are better models out there, but this is such an improvement over my old interface that I'm very pleased with the results.
 
 
Alistair C.
 
 

Good choice, Alistair. 1st Gen 6i6 is solidly built, while the 2nd Gen looks flimsy.
1Gen.
 
 

 
2Gen.

Thanks for the pictures. You just gave me another item to add to my shopping list. 
*Make sure all inputs/outputs are properly secured*
 
You can bet your boots that those missing nuts are only what you see.
I can just hear the marketing/accounting team saying to the engineering team- "what can we sacrifice in build quality to increase the profit with the new units?" 
"well , if we don't use securement nuts we can save $.12 per unit" - Do it" 
I can see a crackle just waiting to happen. 

This is an aging thread, so maybe the OP already solved for their question.
 
For anyone monitoring the thread though, as an owner of both Gen 1 and Gen 2 Focusrite Scarletts (three units), I noticed a whopping difference from Gen 1 to Gen 2.   I was very glad to sell my Gen 1 units to different up and comer folks via Craigslist (giving them my honest feedback that Gen 2 was way better, but offering my Gen 1s at a better than they could buy price from anywhere else).
 
So I very happily got rid of my Gen 1 units.  I can do things now that I couldn't before.  Real time audio monitoring is kind of big.  I can record Addictive Drums 2 live now, where the performance of hitting the drums while recording and hearing the Addictive drums sound is real time.  Lots of things.  Just way better.   That said, I know there are strong opinions that other makers of audio interfaces are great.  I want to clarify that in using the Focusrite Scarlett Gen 2 units that I have that every need I have is addressed.  They work great, sound great, are easy to use, I get great monitoring while recording, and the price for the units was way lower than some of the recommended alternatives.
 
Value gets a plus 1 in my opinion.