Why not get a ZO instead of an E7 to improve the bass? The accessories shouldn't be a deal-breaker as they aren't going to give you anything that stands out. The DBA02 does have better isolation and it is more detailed. Why not get a B2 instead? They're a bit cheaper and look "prettier" than the DBA02 while being pretty much the same product.
I hadn't heard of the ZO before =p . I've read the ABi review and am both excited and skeptical at the same time (I guess I'm one of those "purists" that'll only use it up to half processing...). Won't I miss a "dedicated" amp when paired with the 2010 iPod nano?
As for the B2, well, it's more sleek, sure, but I favor blue to red and like the "nerdy" look of the DBAs, so it's pretty much a draw in that area...
BUT it comes with a hard case and Comply tips, and free international shipping. Only thing stopping me from forgetting about the DBAs is that they reportedly sound a *tad* better (less harsh highs, better bass extension), but I read a review from a pre-production unit, so I'll keep looking.