They are quite different.
I pretty much agree with thedonutman, really didn't like the profile on the combustions and they just didn't feel as well made. The B on both of them is really good but I guess that is a given at 37" scale, it felt much better than the other 5's I've played.
The ABZ had a great neck, really fast, easy to play and a perfect low action. The passive pickups seemed to have a lot more usable tones compared to the actives in the combustion.