I believe you are correct the A&H use a pcb per channel. If I'm remebering correctly. I believe one I used to run a few years ago did anyway. Makes repairs a lot easier to track down,.Doesn't the MixWiz also have each channel on it's on PCB unlike the Mackie which is all on one board? I may be mistaken, but I thought I read that somewhere. Makes the A&H easier to service.
And Sharyn, yes, everyone does seem to be reccomending going digital. Over at the PSW forums, everyone highly reccomends the 01V, or the DM1000 to the beginners. If I had the money, and didn't need to replace my EQ's and comp., I'd be looking into the 01 to replace my ONYX.
Edit: my spelling really does suck.