Well, Avant-Go asked it's readers what must have features should be in a mobile device, and here's the top 3. Calendar and Contacts list... Easy Sync to PC.... Great Battery Life. How well does your device measure up? 9 more items are behind the link.
We Asked What You Wanted
I think all that this proves is that the average Avant Go user is the traditional PDA user. I doubt if it reflects the opinions of the general public.
I used this alot when I had my 3650. Unfortunately, it doesn't support the 6600 and I still haven't received an email back stating when support will be available.