I've had the X10s a few days now, and while I can't compare them to the TF10s that I've never tried, I can compare them to the UHP 336 (super.fi 3's) that I do have:
The X10 comfort is amazing. You really forget that you have them in after a while. I fell asleep with them in a few times already; that would never happen with the sf3s, which are always more than happy to remind you that you're wearing them.
Bass is quite good, as is expected. Mids are full, warm, and detailed, but seem to peak sharply around 5k. High end is also more detailed compared to sf3s.
Soundstage. Despite its strengths, going from the $40 sf3s to the $170 X10s is like going from listening to a mediocre set of speakers in a large, open room to listening to a great set of speakers in a bathroom. Everything sounds more detailed, but it also seems more like the music is coming from inside your head, as opposed to the sf3s.
Lack of isolation. Lets in a fair amount of outside sound compared to sf3s.
Boo on not having an easily replaceable cable.
All in all, I like them, but I don't like them $170 worth. I think I'm going to also give the TF10s a shot and see how they measure up.
I find the isolation on the X5s to be very good (particularly with the bi flange tips)
These are very comfortable.
I feel the thin wires and the thin strain relief could be a problem as time goes on.
I prefer the RE0 for clarity in mids and high end extension.
X5s have more bass quantity and are warmer in mids, but i feel the treble is not as crisp as the RE0s. Wiith clear bass on the walkman, i prefer the RE0.
interesting... my tf10s are on the same level of isolation as the x5, x10s. i also use the double flange and even the shure olives which go on and really lock down. i've yanked the cable; after hooking it on a table edge and got no damage. point is that it's better than it looks. not to say that it can't be damaged but does quite well in the real world.
i bounce around from the different phones depending on my mood. the tf10s have much more detail but are fiddley needing an adjustment, much like moving a full size headphone back into position. this is something i never need to do with the klipsch.