Well, I just got back from my trip to Darien Lake (one of many!)...
And my personal opinion was that there was STILL some choppiness, but that I guess is to be expected.
I didn't feel any air-time (however, I only rode once, and in the 3rd car)... which was kind of heart-breaking because over the winter, I am really looking for a local coaster with good air-time!!!
Anyway, whatever they did... it kind of seemed like it was rough, yet I didn't really feel it.
They had shock-absorbers or something done to the trains where it felt like it was shaking during some transitions, but you couldn't feel it all that much. Plus they must have gotten some kind of new backs on the cars because those head rests are extremely comfortable (though, I don't lean back on them at all... but if it was jerky, it'd be something nice to lean against).
Maybe it was the time-of-day or the weather, but it wasn't airy with lift... but overall MUCH MUCH MUCH MUCH more enjoyable than the years in the past. I'd definately re-ride that coaster, and will by trying every seat to find out which one is the smoothest, fastest, and funnest (is that a word?).
If you have doubts about Darien Lake that you never visited it... just do it!
I never give it the credit it deserves because it's my home park and I'll critize it until the day it dies... but it's really a nice little Six Flags park. Just watch out for the severely cloned Mind Eraser Vekoma suspended. It's the roughest coaster there, and should be replaced with a B&M suspended. Vekoma suspended coasters really just blow the overall experience of fun.
Otherwise, you can have a lot of fun there.
If you are from out of town and are thinking about re-visiting the park from either last year or the year before... no real changes, and not worth it unless you use the campground! (it's still a nice park, however).