I bought an 8GB unit off of eBay from Hong Kong (poly_treasure). With shipping, I paid just over $170US. It took about 2 weeks to get here, no problems. The player sounds awesome with my UM1s. My hard drive players are an H120 and 5G Ipod (with RSA Tomahawk) - they provide a good point of reference. The sound is full and balanced. The player doesn't sound good with my PX100s and doesn't have the power to drive my SR80s. It also sounds like crap with my Senn CX300s.
The touch pad is very sensitive and requires a bit of focus to work with. The menu system is a close clone of the IPod; although, you can browse by ID tags or folders. What I don't like about the IPod firmware, and the M6 firmware, is how you have to back out to the top level menu to return to the 'Now Playing' screen.
The player operates in MSC and MTP modes. It supports M3U playlists, which can be made on the player (just like playlists can be made on IPods).
I can't say enough about the synergy between this player and my UM1s.