I can chime in on this. I owned a Plinius SA-103 @ 220w into 4ohms which is class A biased driving a pair of Legacy Audio Focus speakers @ 95.4 db sensitivity. I always felt like it lacked power. Indeed, there were certain passages where I would drive it to clipping. One of which was Loreena McKennitt’s vocals on the Dante’s Prayer track from the Book of Secrets album. I decided that was unacceptable and that I needed more power. I sold the SA-103 and purchased a SB301-MKII class A/B which is 470 watts into 4ohms. The difference was amazing. I had all of the great Plinius sound and none of the "lack of power" issues. The bass was driven with much more authority, the highs were crystal clear and well defined. I wasn’t quite sure what to expect but now I wouldn’t trade my amp for anything. YMMV but in my experience the additional power of the class A/B amp trumped the class A hands down.
