I have a full rigid single speed as my only bike, and I ride often (daily if I can manage), including some long endurance rides. With a good set up and on appropriate terrain (rocky & rooty New England single track up here), I do not feel it has held me back. I did not spend a lot of time on a suspension bike (1 year on a hardtail), so I might not know what I am missing, but three years into rigid single speeding, and I am digging it.