ive owned both players. returned the h10 and got the micro. (obviously i prefer micro) so here is pro's con's IMO.
H10
Pro-Color screen, sleek look, random play seemed more random. displays clock on main screen. Mistikriver forum
Con- froze up a lot, must use WMP, horrible w/ Napster to Go and similar services because the clock looses a minute every night. scroll wheel would get stuck a lot meaning you having remove battery to reset. playlists are always missing something or dont show up at all after sync. (perhaps some of these have been fixed through firmware updates)
Mico-
Pro-reliable, owned almost 4 months no problems whatsoever (including jack) sound is superior, neon light is nice. touchpad is awsome once you get used to it, software is good. playlists transfer more reliably then h10. can also use as harddrive and sync w/ outlook (not that i ever use these)
Con- battery life is shorter than they claim (i average 7-8 hrs), random doesnt seem that random at times. when power off goes to standby for 24 hrs (meaning battery runs down a little even when off) supposedly a new firmware is coming out to change the 24hrs to 4hr. (i think) also havent found any micro forums that i like.
Creative has supposedly fixed the jack problem in their newest produced micros. not sure when these shipped or how you can confirm that your purchasing a new one.
HTH