Even though I'm not really completely satisfied by any of the currently available Maemo music players, this is IMO one of the better options currently available.
Pros: - Stable; I don't remember any crashes so far - Maemoscrobbler support is a very nice feature - The kinetic scolling both looks and works nice
Cons:
- Battery gets drained in a couple of days if I leave this running (even on background). However, to be fair, I think this is caused by a SDL feature/bug instead of a Kagu bug, see: http://bugzilla.libsdl.org/show_bug.cgi?id=323
- The playlist management (adding/removing/rearranging songs in the list) is a bit clumsy and basic at the moment

Well, first it failed to to install from here (), had to install Python (http://pymaemo.garage.maemo.org/installation.html). Then apt-get install kagu.
For me Kagu's UI is not convinient as I prefer Media Player style UI. There are only 2 things I enjoy: 1. Pause on headset button and headset eject (which is really cool). 2. Correct interpretation of cyrillic letters in ID3 tags (Unicode only, no CP1251 support).
For #1 there is a utility which works with Media Player and requires some tuning for MPlayer: http://talk.maemo.org/showthread.php?t=21182
For #2 there are some players with Unicode ID3 support.
And yes, it does load CPU hardly.