Go for the carbon. I was in your position and went for it and have never looked back. Superb (and I mean superb) battery life, I definatly get 15 hours +
I like the actual scroll wheel A LOT more. The touch pad thing is so annoying, but with the carbon, you can easily access it and change songs/volume in your pocket
Also, software. Ok, I don't use the drag and drop much, but it's a godsend when I do for backing music up, giving friends songs etc. Windows media player is great at syncing (not sure if the micro is compatible). Media source/nomad explorer etc are terrible, I've tried to used them with my Muvo TX and was appauled! I haven't actually used Rio music manager yet but it's meant to be quite good.
Now, the negatives. The static thing (very easy to fix, don't worry) but it's lacking the removable battery, but the carbon's battery isn't gonna die like the ipod's I'm sure. The accessories for the micro are good as well, and remotes are handy, but when using such a small player, it's not that important.
The navigation is great on both (apart from the touchpad) with the micro's being more advanced but the carbon still works great. A few firmware updates and it will be perfect.
Hope this helps