If you like it, then that's good for you, but the DT770s were just weak to me. And if you try to up the bass on them, they start to distort like crazy. Everyone calls them bass-heavy, but they really aren't. Not by a long shot. Yeah, the sound is airier, but it's also a lot thinner. If you think the M100's sound too "meaty", then yes I would agree that the DT770's are a better choice for you. But no, the DT770's do not, by any stretch of the imagination, offer the same bass. They're not even CAPABLE of it. Take an EQ or an amp with bass boost on it and up the bass on the DT770's, turn up the volume. Enjoy your clipping, crackly sound. The M100's won't do that.
The sound signatures are just different, and that's where you'll prefer one to the other. The M100's are aggressive, they're up front, they pound your head in. The DT770's are open and fluid. They let the sound float. Portability and style aside, they just cannot hold a candle to the punch and crackle the M100's have. Like their name suggests, the M100 are a firecracker of a headphone. The DT770s are more like what I'd use for studio work.
I've had mine for over a year and I'll be selling them to a friend fairly soon. They just aren't fun to listen to, aside from not being able to really take them out of the house.
Oh and cross your fingers you don't break the cable or the headphone jack on the DT770, because you can't just pick up a new one for $15, you gotta get a whole new pair of headphones.