Thought from a User...
OK, I am going to throw my 2c out here, for what it is worth.
I have been a Treo user for about 4 years now, starting with a 600, then a 650, then a 680. Great stuff. But, the OS was slow and could never handle 3G, so it was time to move on.
Hated the Tilt and Tytn (had both). Nice phones, but the Treo ease of use becomes VERY addictive. So, I returned the Tilt and got a Treo 750.
Got the phone prepped and installed the WM6 upgrade from Palm. Wow..worked fast, great graphics considering the res on the 750, etc. But, then in a few days, I discovered I could not access my online banking! It has to do with proxy settings and such that MS/AT&T installed. And there was no way around it, according to Palm. I was pissed, but said, ok, I can always make a phone call to see how broke I am (smile!)
I went to set up the auto-pickup - well, it's not in the 750! Palm had no explaination as to why. I really liked that feature on my 600 series phones. So, I was pissed again.
I found phoneAlarm, and tried it - would not work on my phone AT ALL - ZILCH! Nothing - nada. Removed it, installed sPB's phone suite - well, it worked sort of, the autoanswer works great - except for a "feature" that MS included in WM6...
It seems that they feel that even if you are wearing a BT headset and it is active, you must want to use the handset if you answer the phone using the handset button! If you wanted to use the BT headset, then you would press the button on the headset - WHAT FLIPPIN' IDIOT AT MS MADE THAT STUPID DECISION?
I was fed up, tired of being less than satisfied with my phone - hell the 680was slow, but at least it worked! In the end, I returned the 750 that had been flashed with WM6 and got an older, WM5 version - and wow, everything works right! I can access my online banking, the phone software I added works; and with the hack, I have HSDPA speed, although I really would like the HSDPA symbol up there...I can live with that!
I guess the moral of the story is if it ain't broke, don't fix it! Be VERY VERY careful of upgrading to WM6...it is not pretty!