Ok So I am on Rogers with a BB 8900. Went from .348 to .411 (V 5.0 OS's). Here are my findings so far.
1. Boot is faster then .348 for me.
2. Battery Life has been improved. I'd say an extra 20-30 minutes of talk time.
3. I still have the white background on non homescreen menu's, but it just has to be reset after battery pull
4. Internet Browser is MUCH faster
5. Official download of the new .55 BBM works.
6. More free memory, and the memory leak (As phone stays on available memory decreases) seems to be stable around 99mb for me (starts at 104mb free).
7. I upgraded without doing a wipe
8. I have threaded sms without issue
9. GPS position acquisition is faster
10. Themes work, but after battery pull need to be reset
11. WiFi is super stable (Youtube works flawlessly)
12. UMA crystal clear (although, had issue with one router with static, but it was some cheap no name brand)
13. Apps that are working:
Windows Live
AIM
Yahoo
BBM
Google Sync
Google Maps
Google Mobile Search
edocrab
Trapster
Nobex
SmrtGuard
Tumblr
Seesmic
Qik
Score
Leave it On
iSkoot
Flickr
talklikeapirate
poynt
ProOnGo
Docs 2 Go