So far I like the 8125 after using it for a week.
Biggest problem … diabetes software but I still have my Treo and an Zire. The Treo still works of course and switching to it just takes moving the SIM.
Gmaps doesn’t work but Virtual Earth Mobile does.
The Internet and email works much better. Syncing is easier. Actually everything I do on a regular basis is easier on the 8125.
I have ordered a case similar to the case I have for the Treo. Silicon that takes little extra room. I have also ordered a screen protector.