You deff wont be dissapointed.
I have had several WM5 platform phones (and WM PDA's before they went to the phones) and the BB has been the most stable platform I have used (including Palm). WM5 only advantage (in my opinion) is that you can automatically view, edit, and create with the WM Word, Excel, and PP.
For my BB I have the DocHawk program (1 year subscription) to view the attachments I receive. Contstant problem with my WM devices where numerous crashes, and freezes.
Also the WM platform applications gobbled up a lot of memory.