I just downloaded the new version of Missing Sync, and thankfully it comes with a Mark/Space conduit for AvantGo plugin which works very well.

I've only had my Treo 650 for 2 weeks, and I'm quite pleased, basically right out of the box. I use Mac OSX 10.3.8 (also new update), Missing Sync 4.0.4, isync, and everything is rocking. I just use what came on the phone, even though I know lots of people are into downloading and using all the other programs, but I'm fine for now with using Versamail, Web and/or Avantgo (great that you can just surf with it now), Vision, etc. I wouldn't mind a better MP3 player and a better voice recorder that I can also sync. I downloaded some voice memo software off here and I can't get it to sync/backup.

Oh, one thing I don't see, is the Treo 650 show up in iTunes like my Clie used to. But I can just easily transfer files to and from the SD card (which I got free from Palm's website, 128 mb).

Oh, I found a program that easily changes your AddressBook contacts into a CSV file to upload into Gmail (which rocks with Versamail POP, by the way)...
It's called Addressbook to CSV 1.1 and I found it using Google.

So to summarize:

Treo 650, sprint, vision, OSX, Missing Sync, Gmail, free 128 card, = me happy!

I'm waiting for the 650 version of the Codi case, and although I'd love a fancy bluetooth hybrid stereo headset, I think I'll roll with a stereo hybrid retractible headset so I can listen to tunes and hear my calls in stereo.