I rode the "Doohan" last week.
After reading the concerns here before going, I was a little worried about any pain experienced on the ride.
I am 194 cm, about 110 kg.
I did remove my shoes before riding as it looked like I would need all the leg room I could get.
I slipped into the seat no problems and pulled down the restraint, but it wasnt till the back restraint clamped on that it started to get uncomfortable. I could feel my thighs starting to cramp and my toes were sore from being "point on" to the the bottom of the foot holds.
Fortunately, the ride start was delayed (a seat restraint on another bike wouldnt lock in) and it gave me time to make a few adjustments to my poitioning.
From then on it was an enjoyable ride, but I agree with other posters that they could fill up each train to move the line along abit quicker.