Quote Originally Posted by L.J.
So the benefits to amping the mains would be for musical purposes since HT requires a calibration of the speaker levels?
Not exactly...more amplification adds more headroom and better sound and control over the speakers for any purpose, music or home theater. At lower volumes the differences will be very small, maybe not noticeable. But as you start to go louder you can hear notice improvements rather quickly.

Would lets say 200 watts at the same level of 100 watts make a huge difference than overall sound?
No. IMO, double the power isn't really enough of an improvement. IF a 100 watt amp is at its limits where sound quality starts to deteriorate, a 200 watt amp isn't really that far away. It's more of a small difference. For some speakers though, 200 watts will be enough where 100 watts might not be. Usually people are advised to at least double power when upgrading amps (all other things equal), but a factor of 2 X isn't that much when it comes to power.

I was also wondering whats the difference in using a pre/pro+amp combo vs. using a avr with preouts+amps?
Pre-pros generally should have a better pre-amp stage, especially for analog sources. Just a bit finer musical quality. Amps amplify signals they receive from the pre-amps, so if the pre-amp signal is better, the output from the amp should be better. For digital sources, the differences are much smaller usually. For analog they can be significant, especially if you're connecting a turntable with phono inputs in my experience. Huge difference.