I also use the DFX 12. That mixer has AWESOME sound. not only do you have your basic EQ function for each track, but there is also a master EQ to top off all the sound. This is the third mixer I have used in my studio, and by far the best.
I think it is really important to use a mixer to fine tune those sounds.
I use it alot to beef up those beats. I will run my beat through the mixer, tweak the knobs and the effects while recording to a cd, and then I rip it back off the disc and resample into the mpc. Then I drop the sample bit rate, run it back to the mixer and once again, adjust those levels.