dseltz,
I've heard, and really liked, the Charney Companion with the BD3 driver, in a system driven by a SET 300B amp. While this amp does deliver more power than a 45 SET, I know your system can get quite loud while remaining clean. It is hard to say what others feel is loud, and your room size and characteristics do play a part, but, if it sounds good to you don't worry. Even if you exceed 25% of rated power, at peaks, so what? You will not be hurting anything with your setup and your ears will tell you if you are clipping excessively.