My T2 Pro's arrived recently, and yes as all the reviews say, they have a large amount of high frequencies.
However, these headphones are not sibilant, the high frequency boost is not in the painful range, its a more pleasant simmering of cymbals frequency, the boost being around 10-12khz. this boost adds texture to vocals and guitars, punch to kicks and snares, and overall sparkle.
The sound stage is very broad surprises me with its openness for a pair of IEMS, although it doesn't stand up to a good pair of over ears.
The bass is not for bass heads, the highs highlighting smooth mids and an overall flat response minus the apparent high boost. The bass however is clean and has a good amount of extension.
The different ear tips are a nice touch to the purchase, I think I have oddly shaped ears, and (including foams) fit the smalls of the large, medium, and small hole sized ear tips. The T2 pros having metal housings aren't the lightest of IEM's, and they aren't the comfiest, but I can wear them comfortably for a day (on and off). They protrude slightly from your ears, so you wont be able to sleep with them on.
In my opinion the foams and large holed ear tips are the best sounding. The reason for this is because they both have large openings, and allow all the transients from the drivers to be let through. having the smaller openings reduces some high frequencies but also reduces the sound stage by a similar amount and to be honest, I quite having a big sound stage. the bass also increases slightly, but intrudes on the low mids which is not good.
With the large holed ear tips or foams in, the separation between instruments is pretty good. allowing for different details through mainly due to that high frequency boost.
The build quality of the ear pieces is very good: they are solid in the hand and have metal housings. The cable is very flexible and solid as well, although it is more consistent with the feeling of a rope than an electricity cable which means they tangle fairly easy. The connector on the end of the cable is also very solid... and heavy which makes it slightly annoying, but its not a huge hindrance to daily use.
Overall, these headphones have a solid build quality, fairly good build quality and comfort, and a sparkly, crunchy sound signature with a wide sound stage and great clarity.