I don't believe I ever had a Symbian device . . . I used a couple Sony Ericsson phones with what I believe to be a proprietary OS. In 2006, I think it was a K510. You could run Java apps on them, but I only installed one ever (a streaming music player).

I stuck with Palm until my Handspring Visor Prism died of a broken port. I had to back up my data as quickly as possible before the battery died and took the volatile bits along with it. Fortunately, my second S-E, a K550 had an IRDA port and a removable memory stick, and my computer had a memory stick reader.

For a guy who needed a calendar, a contact list, check register and grocery list, the PalmOS was perfect. I doubt I'd installed more than 3 or 4 apps beside the built-in ones.

Handspring's custom version of the calendar app had the neat feature of being able to look up sunrise and sunset times on an arbitrary date. More useful than it sounds when planning events held outside or with older folks attending that don't drive after dark.

I never knew any Blackberrry users who didn't get the phone issued by an employer. It seems like an business executive thing. The keyboard was handy for texting in meetings when they got bored. And the security (or at least perceived security) was its big selling point.