Should I replace my Peavey Audition 20 watt amp with a Marshall MG15MSII Microstack Amp?

If you want a really good Marshall at an even cheaper price than the Microstack I recommend the Marshall MG4 Series MG30FX 30W. It will have a much more full sound than the little 15 watter, and it's a 100 bucks cheaper. A buddy of mine has the 30 watt and it sounds awesome.