I own & use LBP for Windows & have been using it on my Treo. I was an early Treo adopter & agree on the applications support for non-phone software.
But the Treo has become outdated, and Palm has struggled to keep up, not releasing significantly new designs of software or hardware for several years. (latest Centro is technologically identical to the old 680...which I just sold on eBay.)
I looked long & hard at the iPhone and the Blackberry before making my choice. The iPhone has the overwhelming majority of the applications available out there, and is getting new ones every day.
But I learned from my Treo days that my #1 priority for my phone is that it's a good phone first (the Treo 680 failed me there). As far as I could tell, the iPhone & BlackBerry tied in their phone functions - both work well.
My second priority is communications, and that's a close second. The Blackberry spanked the iPhone in this area, both due to its decade-old corporate integration and due to its hard keyboard.
My company supports both, but the iPhone users are mostly left to their own to get communication working well. Only the tech-iest of techies are happy with its corporate integration.
So I chose BlackBerry.
I have added several apps to my BlackBerry, which have been quite useful. eWallet & Beyond411 have been the most-used two so far. Google maps & Ringo are working well too.
BUT - now I need to make a decision on the Logbook software. Do I abandon Logbook pro because it's now obsolete, left in the dust by technology? I'd much rather buy a BlackBerry version & keep synch'ing without having to take post-it-notes back & hand-enter my entries later.