I took a chance with installing ActiveSync 4 and WM5 on my Dell X50 (Aug 2005 vintage). To head off any ActiveSync TCP/IP problems, I also followed Microsfot's advice about unbinding the Mobile device from some of the Network Settings (microsfot.com/mobile). Everything seems to be working great. I will say, however, that I did not immediately restore my data for fear that something may not be compatable. So I'm reinstalling stuff a little at a time.

So far, I love WM5. The sync takes longer with ActiveSync4, but all else works great. I have played media files, synced with two computers (home and work), and tested the wireless capabilities.

I had noticed that my unit seemed slower, but I fixed that by forcing it to top speed in the Power menu. Also, no battery drain trouble. 78% when I went to bed, 78% when I woke up.

Maybe my luck is attributable to the fact that I'm not a power user and don't have a lot of non-standard software on the unit?