Class-D or switching amps, any opinions on??

Does anybody have experience on Class-d or switching amps vs either a/b or traditional amps?? I have heard people knock them for limited ability at the low frequencies. However, I listened to a Linn amp not long ago and could not hear it wanting for anything. I want to hear a Rotel switching amp to compare. Why buy a massive 90lb amp thats a space heater if you dont have to, right???