Sbrtoy is right.The monster SS amps will become dinasours if they are not already.Many of them also sound apalling-some are reasonable, so the belief that heavier is better is a flawed generalisation.Most lightweight chipamps and the newer breed of PWM /digital type amps like NuForce sound better,run cooler and are comparatively very light.Not to mention much cheaper.Audio retailers hate them for this of course.
Tube amps are a different matter however,although I have heard some very ordinary sounding monster SETs that are not as good as a much lighter PP types.
Let your ears do your buying,not your eyes or muscles.