I have been a full-time musician for the past 11 years. A couple of years ago I looked into upgrading my stuff and was searching for a new mixer. My top three were the Mackie 1604. The SoundCraft M12 and the Allen&Heath MixWizard stuff.
I purchased the Allen&Heath. And I have been VERY happy with it. Some of the reasons I went with it are these:
1) They are quite rugged. Meant for the road. Also, they are very easy to work on (not so with the Mackies). Also, I've been told by repair guys, that the SoundCraft's don't like to be moved around alot. That is, they don't hold up well on the road...
2) Sound and flexibility (this should actually be number 1...if I were listing these in order of importance). The sound of the board is much warmer than the Mackies. It also has 100mm sliders. Also, there are 2 sweepable mid EQ's per channel. A VERY cool feature, if you've never used a board with it! Also, I was told by a tech guy at Allen&Heath that the MixWizard uses the same preamps as their GL 2200 series.
3) Direct outputs and 6 aux's. Direct outs are a MUST if you want to use this board for recording. The aux's are also group into 2's with switches for Post/Pre Fade.
4) Individual channel phantom power switches. This might not be a big deal...unless you run condenser mics...and have lost power on a universal Phantom Power setup...
And, though I didn't find this out until later...5) Tech support. Allen&Heath have been very helpful. I had a little trouble (nothing that couldn't be fixed) with my originanl board. And, seeing as I am full-time and cannot afford downtime, I was in a bit of a quandry as to what to do. Allen&Heath shipped me a replacement (as in, brand new) board and allowed me to keep mine until it was received. Since then, I was having trouble with the faders on a couple of channels. Allen&Heath sent me the parts (enough to replace EVERY fader if I so chose) talked me through the problem and allowed meto fix it myself (which was very easy, by the way)
So, as I have stated, I am very happy with my Allen&Heath and would highly recommend it.