Great question about volume level. I have thought about this issue as well. Here is my opinion on this. I went from an older pair of 3A Signatures to the Treo CTs. I have noticed myself getting up to turn up the volume much more frequently now with the Treo CT as opposed to the 3A Sigs. I believe I'm doing this because of the clarity and smoothness of texture of the Treo CT versus the 3A Sigs. I always wanted to listen at a "realistic" volume but the 3A Sigs. lacked that clarity and smoothness of texture. I found myself turning the system down.
I've always considered the volume issue to be a bit of a judgement on the sonic quality of the system. The better the sound, the greater the temptation to turn up the volume. So...your desire to turn up the volume to get things to come alive is to me a good sign for the sound quality of your system.