People on Head-fi.org compared it to Xelento and said that it's more fun and better value. I don't think it's comparable. Xelento has more bass and fuller bordering on boomy with warm low mids and very tame rolled off treble.
M3 on the other side is bright, with rather aggressive lower treble. The upper treble is extended at least to 17K and I believe beyond that, not looking at the graph.
Resolution and treble detail wise it blows Xelento out of the water, but overall tonality is better on Xelento as well as M3 sounding more V-shaped with better sub-bass but overdone lower treble.
That said, in this price-range there are no competition, given that aggressive V is your thing. That ABM driver resolves details of the percussion and strings like even EST IEMs cannot. It's a shame that Wizard of Noble Audio squandered the chance of creating a true masterpiece annihilating everything in $1K+ range. All components are there but tuning lives much to desire. Of course, it's an audiophile perspective (the one who doesn't like recessed mids).
Build quality is high. It's sturdy, heavy, 2pin connector is tight, on par or better than Legend X. Unlike Legend X, there is no driver flex in M3. Isolation is among the best, topped only by se846, AM05, and other solid resin all-BA IEMs.
Comfort is very good too, fits flush in my medium-sized ears, can sleep in these.
I inserted small pieces of foam in silicone ear-tips to tame lover treble and that unmasked upper extension, opening up a grand sound-stage. With this easy mod M3 is a keeper even for me. :)