I have reviewed the Comply S series a little over a year ago (see the review here) and compared it to the T and Tx series. At the time I have came to the conclusion that my personal preference is still the original T series in general while on some occasion, I do find the Tx series to work well to add warm to analytical IEM while S series provides easier fit. The reason for my preference for the T series is simply - it is the least intrusive when it comes to sonic effect. Like any eartips, foam tips also affect the IEM sound as the foam itself tends to absorb more treble and add warm to the overall sound, which can be a negative trait if the IEM is already warm sounding. But even with the T series, it is still impossible to avoid some level of treble absorption. The Ts series, while not really aims to 'fix' that issue, has actually turned out to be the least intrusive of all the Comply foam I have used (and I have used almost every models of them).
Ts400 (left, all middle sized) next to T200 (right, S, M, L each a pair)