I like this mixer a lot...
I bought this muxer to replace my rack of equipment consisting og a peavey USB 14 mixer, Peavey PV1500 power amp, Peavey equalizer, and Lexicon MX400.
Well, I'm still using the Lexicon (the built-in effects pale in comparison), but the XR 1220 does a stellar job of replacing everything else, and saving my aging back in the bargain...heck, just my rolling rack alone weighs more than the XR 1220.
This mixer has really good microphone preamps. They are comparable to the mic preamps on the PV series mixers. The power amp easily has enough guts to cover a fairly decent-sized venue. I usually play in outdoor setting for audiences of up to 300 people. I run two Mackie Cs300z's and a Mackie 1801 sub, and the subwoofer output is perfect for my speaker configuration. When you set this mixer to use the subwoofer output, it very effectively removes anything below 100Hz from the mains. That makes me very happy.
I give this mixer a 4.5 because of the built-in effects. If you have been spoiled by Lexicon, Alesis, etc. you will find the effects somewhat lacking, but they are usable. There are several types of reverb, and you can adjust some parameters. A nice feature is that you can send reverb to the monitors, so your singer doesn't have to listen to herself "dry" in the monitor.
This mixer has made my gigging life so much easier, it's amazing.
Buy it, you won't be disappointed.