Oh, I'm happy with how it sounds, it's just quite a mess of wires and whatnot, and the amps are a tad bit too big to fit under the seats where I had my previous ones set up, so I'm going to have to relocate. Thinking about moving them to the trunk but not really excited about having to (quite possibly) run a 1/0-gauge wire from my battery to replace the 4-gauge that's already there.. I'm now running about 750-watts RMS total (100wRMS to each set of front speakers = 200wRMS from the Sony amp and then a touch higher than 500wRMS to the Alpine Type-R from the new Kenwood amp) so the 4 gauge wire is probably not going to cut it for long.
I'm actually really happy with the db6501s. I compared them before I bought them and considered the MM6501s but for the deal I got on the db's, I just went with those. Most people who complain about the 'sound clarity' difference between the db series and the MM series are the result of underpowering the db's. I moved my Sony amp (the one pictured above) from my Alpine Type-R over to the Polks up front, and now have the gain at about half, should be ~100-watts RMS/300-watts max per channel and the db's sound b-e-a-utiful!
I am considering, however, eventually adding a second set of components up front, in addition to the ones already installed (second set of woofers in kick panels, second set of tweeters on the dash/inside A/C vents).