Hmm, let's see.
I own:
DT880
DT770 Pro/80 (considered the bassiest of the DT770s)
Owned:
XB700
M50s
AD700
I can EASILY say the XB700s are the funnest, bassiest headphones of the bunch. No kidding. Yes, the bass is MONSTROUS, but they have a pretty good level of clarity in the mids and highs. They are not audiophile headphones, but easily my favorite sounding of the bunch. I found the DT770 to be muddier/less clear than the XB700s.
If you want destructive, PUNCHY bass, the XB700s will be fine. It's just that people here are spoiled by overall balance, that anything less than that is considered crap. The XB700s are NOT crap. They are AWESOME, and not ONCE they I find them unclear in their sound. For $80 they are a steal. I had to give them up because the stitching on the pads didn't agree with the side of my head where they rest. If it wasn't for that, they would be my go to headphone for getting lost in the music. No doubt about it.
My ABSOLUTE FAVORITE sounding headphone, ever. Just remember, the bass is definitely HEAVY to the point of making you lose focus on everything else. If you want balance, look elsewhere.