Love my Kreitler rollers - yes, it feels pretty sketchy when you get on them (I liken it to riding on ice) but your riding skills will increase dramatically. I think using parabolic rollers defeats the purpose of building the skills you get from rollers. I ride next to the breakfast bar in my kitchen (good height) or the work bench in the garage or someone next to me on their trainer (use their bars as needed) I did almost 2 hours on my rollers this weekend (it was blowing like crazy outdoors) and I would never be able to stand 2 hours on the trainer, too boring. I watched 2 of the "Sufferfest" videos. They aren't great, but they are free. Tokie