I can't recommend buying the X-IE at the moment due to build quality issues. I like the M2 better than the PS20 and TS02. The PS20 is more of a smooth, relaxed sound with less forward mids and lower bass impact. The TS02 is more v-shaped, again with less forward mids, a bit more treble sparkle, and similar bass impact with a little more depth. The PS20 has the widest soundstage. For more specifics you'll have to read the reviews - I haven't listened to the TS02 in a while.
Then I think I will need to stick with the M2's only