Review/feedback after a month?
Did you keep the 7100t? If you did, could you post some additional feedback on your experience, especially with the tasks / categories functionality?
Blackberry works well for GTD
I recently picked up a 7280 (on ebay no less) and started using it with Outlook for GTD. It's a little different than the 7100, but the software and underlying hardware are pretty similar. After using it for a month now I can say a couple of things about it, using it only as a PDA/phone (I'm not giving AT&T the $$$ for data services)
It does work well for GTD with the OS 4.0 upgrade (adds categories to todo and notes). The biggest issue for me is that this provides me with basic palmpilot functionality (addr/cal/todo/notes) in the same object as my phone so I'm not carrying 2 devices around. I found that when I was carrying 2, I tended to not take the palmpilot with me everywhere, and that negates some of the GTD usage model of writing things down right away.
As a phone, I'm really happy with it. It seems to get slightly better reception than my SonyEricsson t616 on AT&T/Cingular, and I'm in a pretty dead area, so that's a major issue for me. I though the form factor would be annoying, but it's not the issue I thought it would be.
Adding apps is easy, but I've been less than thrilled with the volume and price of apps. Maybe I got used to 1000s of free apps for PalmPilots, but there's not as much out there as I expected. I'm really looking for an etext reader, a Bible reader and maybe a zmachine emulator to run zork on and all three of those don't seem to exist (please let me know if you have any of these 3).
Syncing to Outlook 2003 is EXCELLENT. I don't have a Mac, so I can't comment on that side of things.