I have the 1st generation 2i4... when it works, it's pretty good. There has been some driver issues with windows ten but it seems to have stabilized. My issue is that Focusrite will have drivers in beta for YEARS. Leaves you wondering if there will EVER be an update. From what I can tell, once the product hits the shelf, Focusrite stops driver development.

I bought the Scarlett 6i6 about 3 years ago because my Tascam us1641 had sloppy drivers that caused me grief from time to time.
The 6i6 has great drivers but the  pre amps are totally not acceptable to me. Either to cold or too hot. There's no happy medium. I solved the problem by getting a Joe Meek 3Q pre amp as well as I can use my Yamaha 01v via SPDIF. I have no clue why people claim the Focusrite pre amps are good?
I've used a lot of gear in my life and I'd rate them near the bottom of my list.
Then Tascam released updated drivers for my us1641 and now it almost outperforms the 6i6. RTL is a hair better and it has 100% usable pre amps... and 8 of them to boot. My next interface will be another Tascam ( UH 7000 ) or if I get rich, an RME or Motu.
If your needing good latency performance you will be looking at those 2 brands as well.
 
Tascams us 2x2 is the best bang for the buck at the $150 price point. Has midi and optional wall power and good pre's.

jamesg1213

Beagle
 

I bought a first gen 2i4 and promptly took it back as "defective" but later learned that's the way it was designed.  I hated the way the gains worked on the preamps.  I had to turn them almost all the way up to get any gain and then it seemed like it "crossed over" to a different gain stage so the result was that there was one small sweet spot on the pot that worked, but anything else was way too little gain or way too much gain.  on either channel.
 
 

I have a 2i4, and none of the above problems. Apart from it very occasionally getting 'missed' on boot up (I have fast boot on the PC), it's been just fine.

James - some people I've talked to have said the same thing you have, but others have said they had the same problem I described.  it sounds to me like it is a crap shoot whether you get a good one or not.
 
glad yours works for you!

Cactus Music
I bought the Scarlett 6i6 about 3 years ago because my Tascam us1641 had sloppy drivers that caused me grief from time to time.
The 6i6 has great drivers but the  pre amps are totally not acceptable to me. Either to cold or too hot. There's no happy medium. I solved the problem by getting a Joe Meek 3Q pre amp as well as I can use my Yamaha 01v via SPDIF. I have no clue why people claim the Focusrite pre amps are good?
I've used a lot of gear in my life and I'd rate them near the bottom of my list.
Then Tascam released updated drivers for my us1641 and now it almost outperforms the 6i6. RTL is a hair better and it has 100% usable pre amps... and 8 of them to boot. My next interface will be another Tascam ( UH 7000 ) or if I get rich, an RME or Motu.
If your needing good latency performance you will be looking at those 2 brands as well.
 
Tascams us 2x2 is the best bang for the buck at the $150 price point. Has midi and optional wall power and good pre's.

"too hot or too cold" sounds like you had the same problem I had with the 2i4.
 
I'm glad the tascams are good - I hope their drivers are good, I know they didn't used to be.
 
my MOTU is still the best piece of equipment I've ever owned, but of course they aren't cheap.  the roland Duo is really nice, actually for the price.  it's my back up unit. 

I have a first gen 18i20 and still really like it.  It's been reliable and flexible interface.
I don't see myself growing out of it any time soon.
My only (minor) complaint is that the preamps could not adequately drive a ribbon microphone.  This is a fairly common issue.
I ended up purchasing a cloudlifter and that solved the problem.

Like Johnny V/Cactus I have the us1641 and a Scarlett, though I got the 18i20(version 1), for the same reasons. Both of mine have worked well, sound good.  I haven't really thought the Scarlett's pre's are inferior. I have been thinking of "trading up", but since my desktop doesn't have usb 3.1 nor TB, I figure I'll take my time on it and aim for "moving up" to better preamps and RTL.
 
Michael

I'd like to append/amend my comments. It dawned on me, I only use the Scarlett pre's for DI guitars/bass/keyboards (actually those are all routed through the OctoPre MKII Lightpiped to the 18i20). I don't think I've actually used a vocal through it, as I usually route them through my other preamps into the line ins on the Scarlett. It's my habit to use external pre's into it, so I actually don't have anything to compare.
     I have done bunches of vocals through the us1641 and I do think they do fine job. I imagine the newer Tascams are way better.

Buying now you would get the 2n generation which is excellent. It has a large input range covering from low to high output levels of microphone and instruments(if too hot after de-selecting instrument, the Pad switch will knock down -10db). Low latency and good mixer options via Focusrite control. I have the 6i6 which has a separate power supply so not drawing from the laptop usb. The software seems robust always connects even when laptop woke from sleep and I turn power supply back on(couldn't do that with old FastTrack one).The build quality looks and feels excellent too and sits solid on desktop.
BTY- there was a good review of the range in the November 16  Sound on Sound magazine.
John

I got a 2nd generation 6i6 this summer and it has worked flawlessly since the moment I installed it. I can't say it's the best interface for the money, but I have no regrets.

I've just got a 2nd Gen Solo - very pleased so far, apart from the fact it doesn't seem to 'play nicely' with Sonar BitBridge.
If I insert a 32bit VST instrument using Solo I get rhythmic pops/clicks in the audio. All 64bit VSTs are fine.
(I've done all the usual troubleshooting / fixes to try and clear these). Also, if I use the 3rd party 'JBridge' wrapper for a 32bit VST then this appears to sound OK - so I can only assume it is an incompatibility between the Focusrite drivers and Sonar BitBridge.
32bit Effects are fine, only 32bit VST instruments seem to be affected.