In my experience, 1W with volume full open is about as load as a 100W with volume on 2-3. So it wouldn't necessarily appear louder or quieter, but the tone is SOOO much better because the amp is really working

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Besides the sound, there is also something about the feel that changes when you play. It feels great. It's sort of a different response. You should try it out in a shop or from a buddy or something!
I played my 1 watt head in the middle of the night yesterday with great tone, and quiet enough not to even wake up people on the floor below. Since most shows have PA, i really don't see the point in 100+W amps anymore...