Rick, the preamps are pretty much unhyped from top to bottom and sound right. Compared to the VLZ stuff the Onyx preamps are full range without top end tizziness. The gain is pretty smooth top to bottom. The sound is very all purpose and I've used them mainly for drums, but they work well with all sources from acoustic guitars to vocals to elec guitars. I like the fact that phantom is selectable per channel and not grouped.
The EQ is wonderful...when it hits. The Q is rather wide on the mid adjustment and cannot get surgical but it is quite musical. The problem of course is that the EQ is only going to be available when sending out the busses or main outputs to use the strip. The direct outs are mainly post preamp and pre "everything else" including EQ. Being designed for live sound and recording it's great, but they should have made it an option in my opinion. I don't record drums with EQ most times so for me it wasn't an issue, I bought one for my personal studio because I need a bunch of drum preamps.
But yes, the sound is right and it's dead quiet too. Mackie's claim of "good as boutique preamps" depends on who you're talking to I suppose and more marketing hype. Mackie did however get the preamps sounding very tight and focused this time around.
My biased (dealer) opinion, but I am an Onyx owner too!