I'm sure all the bleeding edge / leading edge / did they release WM5 too soon topics will continue to inspire a huge variety of opinions for quite a while. My own experience with WM5 has been very good. Have had issues, but have found solutions to them - a lot of them through very helpful tips and suggestions found on this site. For instance, I definitely recommend the post below from SolSie for some great general tips on common initial heartaches with WM5.
WM5 Here To Stay Tips from SolSie
In particular, you may want to look at this section on battery drain:
ActiveSync 4.0 turns on automatically/Processor stuck at 624MHz ******
There were several posts indicating ActiveSync turns on by itself when the Axim is not cradled and eventually drains the battery. It never happens to me. Circumpvention provided by Invid:
Disabling automatic syncing (and activesync startup) did. The new activesync is a dog, even worse than it was on WM2003SE and makes my x50v almost useless while running. I will list the steps to disable it. Note that you will still be able to sync, but AS will no longer start up on it's own.
1) Start up AS on your x50.
2) Tap the menu tab/soft key and tap "Add Server Source"
3) Configure a server source with a dummy IP address, user id, password and domain name; these do not have to be real
4) Once configured you should have another sync source show up on your main AS screen...continue on.
5) Tap the menu soft key again and you should see that the sync schedule option is no longer greyed out.
6) Change your schedule from a timed automatic start of AS to manual under both fields
7) If you try to sync now, AS will try to contact your imaginary exchange server and that will take forever until it times out, so you can now delete the exchange server from your list of sync sources. Your changes to the sync schedule will remain and will survive soft resets too.
HTH