I'm a bit of a heretic when it comes to mic pres. I like the Mackie pres for good basic sound. To me, they are kind of like an sm57 -- they don't change the sound much. They may or may not be fantastic, but they rarely sound bad.
I prefer using an uncolored preamp, then adding color later as desired.
Using the Mackie preamps (the XDR ones in particular) from the insert outs (bypassing the eqs, etc.) directly to the A/Ds gives very basic uncolored sound.
Note that a number of huge hit records have been recorded using Mackie boards. Bottom line gets back to the music, not the equipment.
-lee-