Too many hours of my day yesterday were lost to making acquaintance with my new Treo 650 (GSM Unlocked). The most obvious new features are certainly a huge improvement-- Bluetooth, high resolution display and a better button layout. Even more exciting than that, however, are the small yet potent improvements to the user interface.
The basic phone applications are finally up to par with phone-centric devices. Messaging is now integrated into one application which means your SMS and MMS messages are all in one place. Chat dialogs even show text and picture messages in-line. The Contacts application can display entries from your contact list and SIM card in one view. After you finish a call, the Treo will ask you if you want to add the caller to your contact list if the number isn't already there-- a feature which is useful, though potentially annoying. But you can turn it off for good. And camera functions are nicely woven into both of these communication apps.