I also use 6i6 first gen. With beta drivers it works like a charm, i.e. runs at 64 samples

Does the 2nd gen Scarlett really have lower latency?

Soundwise
 
Does the 2nd gen Scarlett really have lower latency?

That's one of the claims (I don't have mine yet so can't test it):
 
* Super-low roundtrip latency was measured at 2.74ms, working at 96kHz with a 32 samples buffer on Logic Pro X, running on a Mac Pro and OS 10.11.
 
Obviously YMMV, based on your own setup and settings, but I've seen reports of between 5 to 8ms RTL at 44khz, so yeah, better performance over the 1st gen.
 
None of this is to knock the first gen Scarletts in any way, as they are solid performers. In fact, now's a great time to buy one at a discount as the stores clear them out for the new stock. 
 
The other obvious advantage of the 1st gen is that they're time-tested and solid.  A few 2nd gen users have reported driver issues, so personally I am waiting another month or two before I buy to allow Focusrite to sort those out.
 
Interestingly, I read that Focusrite intends to update the first gen drivers to improve their latency (Presumably with what they've learned developing the 2nd gen), so all Scarlett users benefit from the new tech.

Thanks, JonD. Currently, the best reason to get a 2nd gen Scarlett seems to be their plugin suite. When their will be measurements of better performance of new preamps and RTL in public domain, then more users may consider hardware upgrade. As of now, I'm content with 1st gen performance, but it's good to know Focusrite is going to update drivers.

 I was thinking about getting a 6i6 gen 2 since Focusrite indicates that it has low latency (for a USB interface) but was wondering what latency users were experiencing in the field. 
 
Note: I am currently using an older Firewire unit (Saffire LE) which some have found to be unreliable in Win 10 so I'm looking for a replacement.  The LE has a round trip latency of around 7-8 ms on my Win 7 system.

Soundwise
I also use 6i6 first gen. With beta drivers it works like a charm, i.e. runs at 64 samples

Does the 2nd gen Scarlett really have lower latency?

I can get to 4ms with generation one.The box Is faultless.

Deleted.

Ya , I get the same as Soundwise areound 7.5 to 9 RTL. But that's at 44.1. This goes down if you use the higher sample rates. On my system it becomes unstable so I don't go there. RTL does not matter to me because I do not use guitar sims and I monitor analog before the signal even goes to the Scarlett so I'm zero latency as far as that goes. 
 
Good news if the improve the drivers but I actually have had no problems since the last update came out. Soundwise,, why are you using the beta? 

I'm using 18i20 2nd gen. so I'm listening in for ins/outs. I've had some successes and part was correctly routing within the focusrite routing.

I have had the first generation 2i2 and 18i6.

I now have the second generation 2i2 and two 18i8s.

Although I was satisfied with the first generations, I figured if I could sell my 1st gen units on Craigslist for a decent figure, I could upgrade to the second gens for not that much. Which is what I did.

The second gens are way faster. Noticeable. Totally satisfied.

I run 1 18I8 (upgrading soon to the 1820) and the 4 pre amps are simply not enough anymore.
I went from a 2 pres to a 4 pres because for the user who simply records by himself, 2 mic pre amps are fine.
But for recording drums, I have to share a mic pres with the 2 toms (hi + mid toms).
So essentially im using 1 mic pre amp for kick, 1 for snare, 1 for hi and mid toms and 1 for low tom.
 
I will say this, ive been very happy with the sound of the Focusrite scarlet mic pres' but if you really want pristine quality, I suggest the ISA 1's. or the Claret's. in my case I just need more pre amps so the 1820 will do.