Well not really a review, but I finally have compared the two directly. The M-100s have a more pronounced V-Shape curve. Big bass mids take a back seat (but are still separate and clear, the bass never interferes with the mids) and they have decently (but not overly) sharp highs with roll off in the upper frequencies. The T10i in comparison seem far less pronounced, and depends on the filter. The highs are pretty much equal in terms of rolloff, but the M-100s, at times seem to sparkle a bit more, but the T10i seem more natural. Bass decay and speed are about equal, neither are speed demons. The biggest difference is in how the curve is presented. The bass of the T10i is very linear going into a small scoop for the midrange. Then depending on the filter the highs can either sparkle or remain recessed or just take a back seat entirely. The T10i's are surprisingly more detailed than the M-100s though. That isn't to say that the M-100s are undetailed, but considering how I've heard people talk about the T10i, I wasn't expecting the level of detail on these guys. Even the soundstaging is similar, but I'd give the M-100s that one. (tested with Dr Chesky binaural sound show) But the sound stage of T10i is very 3D. The only IEM that I have that bested it was the ASG-2, which is impressive.
If you are looking for a companion for the M-100s I'd say these would actually fit the bill pretty well. While there are differences they are definitely cut from the same cloth. A fun and dynamic headphone with bass to spare. The presentations are slightly different, but if you enjoy the M-100s I'd be surprised if you didn't enjoy the T10i similarly.
Full review should be coming in a couple of days.