Alright, lets wrap up this thread. I got the DB680 and ran it into a Crown XTI-2000 amp into a pair of eden d210xlt cabs and then a Bergantino NV610.
The aguilar pre just sounds better than the ashdown. It is much warmer and "tubier" and way clearer. It was exactly the clarity I was looking for while still remaining warm. The ashdown is a bit dark sounding in comparison. The abm500 eq is easier to use on the fly but the aguilar can be dialed in with more precision.
That said, I prefered the low mids of the Ashdown. I couldn't quite get the low mids right on the DB680 but it owned the rest of the frequency spectrum. Through the edens the aguilar won hands down. Through the NV610 with no tweeter, things were more closely matched. They both had great breakup and sounded more vintage ampeg than anything out there. I can't believe people saying that the DB680 can't do overdrive. It's perfect.
BUT! I realized that my rack is getting too big and that the tonal differences of the two won't amount to that much at a real gig so......I just sold the DB680 and am sticking with the Ashdown. It actually hurts my hear alittle but I know that Im doing the right thing.
So, the aguilar DB680 is king. The Ashdown ABM500 head is about 80% as good. I stuck with the ashdown and will probably buy the DB680 two more times in the future.

It feels like I just broke up with a really hot chick for no good reason!