I haven't tryed it myself but read 3 tests. All with equal conclusion. Seems to be much too expensive. (my personal estimate: 150$ too high)
This is translated from http://www.journaldugeek.com/2013/01/02/test-flash-ecouteurs-ultrasone-tio/
"The sound signature focused on neutrality is relatively cold, which might seem metal, worn on the treble and less bass, although these are excellent, less clattery than those ER4P, but similar. Restitution would appeal more interested in high fidelity as "bass-lovers", that is certain.
At this price you are entitled to claim a certain level of finesse in the restoration of natural instruments, particularly in terms of texture. Unfortunately, Tio rings hollow, with very little texture, both on percussion on the voice, the Tio has no height, SM3 Earsonics of doing much better.
The separation of instruments is good, without being great, attributing it to a more frontal soundstage that side. In contrast, the stereo effects are good and well treated, without any break. Sounds come from left to right "naturally", but it is never completely immersed in the sound space. The position of instruments is precise, easily isolating each instrument on stage, except where it is deep draft. The SM3 are much better for the level range in which we are. In any case, this accuracy is not never felt acutely, unlike ER4p, real surgeons soundstage. This is clearly softer."