I'm 6'3" and 185lbs and I have no problem. The seat is comfortable to me. It's got a lot less space to move my legs from side to side, but I never really move them side to side anyway.

 

5'9" and about 155lbs.

It fits me almost perfect.
My only issue is with the seat slider. My perfect driving position is in-between clicks. It's close enough that it's not a big deal and forget that it's not perfect most of the time. But whenever I have to move the seat (access seat pocket or cleaning) and I have to re-adjust the seat position I'm reminded of the fact that I can't get exactly where I'd like it.

 

I'm 5' 11.5" (dammit, i just need .5" more...) with most of my height in my legs, and about 170lbs.

the s2k fits me perfectly, although my knees hit the steering wheel if i don't have my feet near/on the pedals.

only difficulty i have is getting in and out of the car.