Well, it all depends on the type of sounds you looking for. My experience is that most players need much less power than they think. If you want to involve the power section in clipping, you need less power and probably Power Scaling---many players can get away with 20W for guitar or less with the right speaker setup. Some guys just like the sound of the bigger amp and that's more of subjective a choice; they don't need the power
However, some circumstances and tonal requirements require high power. These basically any style that requires high volume and cleanly run power section. Some examples I can think of include:
A. high gain in which the pre-amp generates all the distortion, and you need high volume without the power amp clipping
B. Bass when you need clean headroom and no clipping
C. A player who wants very neutral pedal platform.
However, some circumstances and tonal requirements require high power. These basically any style that requires high volume and cleanly run power section. Some examples I can think of include:
A. high gain in which the pre-amp generates all the distortion, and you need high volume without the power amp clipping
B. Bass when you need clean headroom and no clipping
C. A player who wants very neutral pedal platform.


