My pedaling is smoother. I don't rock on the bike. I can go up or down in rpm's more easily and my ride is more fluid. The French call it riding with "Supplesse" which, I think, means suppleness. I do credit rollers. As you know, if you ride rollers you have no choice but to be smooth. I think this is very important when beginning cycling. I believe this gave me a solid foundation from which to develop as a cyclist. FWIW, I don't think it's an either/or situation. I think rollers and trainers can give you different benefits. If I was a serious cyclist, as in racer, I'd use both in the off-season.