I used to have a pair of c1"s, not the II version. I used a Simaudio i7 integrated amp. They played quite loud without any distortion. My room size is 18x12x8. Perhaps your amp is giving you a problem.
In answer to your last question- if your room is not too big, it would be hard to ask "too much from these speakers".
In answer to your last question- if your room is not too big, it would be hard to ask "too much from these speakers".