11.1 PB3 has been running smoother for me than beta 1 or 2. But one remaining problem: battery drain.
In the last two or three betas of iOS 11.0 before the official release, I had pretty good battery life on iPhone 7 Plus and iPad Pro 10.5".
Starting with the official release of 11.0, battery life is reduced - not horrifically, but ~6 hours of instead of ~10 hours. And performance was a bit glitchier than in the last few betas. Things didn't improve for me with 11.0.1 or 11.0.2. At that point, I moved to 11.1 PB2 in hopes it would be better, and it was better in ways other than battery life, though still a bit glitchy. PB3 has been better yet, but still, battery doesn't last more than 6 hours before needing a recharge.
iOS 11 seems to be a bigger upgrade from iOS 10 than iOS 10 was from iOS 9. I imagine Apple's developers have been more focused on getting everything to work fluidly than on optimizing code for improved battery performance.
But I really, really hope battery life will soon improve, at least part way toward what it was before.