AB has its place, but in today's systems there is no advantage anymore. The silicon and designs used in the FETs of today are so far superior to what they once were that the turn on times are essentially instant and the power drive phenomenal. The only legit reason for a Class A, Class B, or Class AB amp today is nostalgia. But that is a valid reason. Same reason I keep my old game consoles alive and working even though I have all the ROMs and emulators.