I've had Palm Treos for nearly 6 years (Treo 600, 650, 7XXp, centro). All with PALM OS, and I wouldn't have it any other way. I spent over $500 (with a 2 year contract) on my first Treo, and haven't looked back. The Palm PRE is due out in the next 2 months (supposed to be the first serious Iphone competitor). I don't use mine for business, all personal, and I'm a text fanatic (like 4k a month), and it is great all around.
I've never had a physical issue with any of the phones, just some small software stuff that they rectified immediately. These phones have been dropped, thrown, and fallen off of motorcycles at 60+ mph, and never failed. My current centro has taken the most beating, and is still ticking perfect. Great battery life, sprint EVDO network is super fast, and their customer support is no longer in India, its in the mid-west, so you speak to pleasant, native english speakers who actually help.
Sorry to sound like a sprint salesman, but I've tried all the others, had crackberrys, iphones, etc; att, verizon, helio, and none of them could compare, I always came back to my Sprint Palm devices.
NEW Palm PRE
Edited for link.