I was almost scared away from the device by the sales reps at the Sprint PCS store. They claimed that when the device losses power (by taking the battery out or letting it die), you can lose some of your contacts, or the entire phone can be reset and need to be re-programmed by Sprint. I couldn't find any mentions of this particular bug on the web, though there were clearly a lot of other bugs out there. They were also careful to tell me about the 30 day return policy on the phone, and told me not to buy accessories in case I return it, etc.
My main concern was actually how well the phone would work as a phone, and that is still my main concern after having it for nearly two weeks. I liked my Startac in that it was a natural phone form, and the speaker wasn't very directional. I've tried to use friend's Nokia phones, and felt I had to hold the phone at exactly the right point to hear it. I've felt some of the same with the Treo, but not as bad. I think part of it is the Treo speaker isn't "crisp", at leat not at high volume. Its also uncomfortable on the ear for long discussions, so I've bought a headphone piece for it (and noticed it came with one) so we'll see how that goes.
Dialing while driving is definitely out. With my Startac, I could dial by feel, or I had memorized the right steps to certain people in my phone book, and a quick glance would be enough to know I had the right person and call. Not being able to dial in the car might be a good thing, or I might get the voice dialing working (but you have to pay extra for that? What?)
Speaking of "paying for it", I was somewhat surprised by the software CD the Treo came with, in that it had a bunch of software on it, some was labeled as requiring purchase, some that was just demo software but wasn't labeled as such (10 games on Tetris? Come on), and some that wasn't Palm software at all, like Realplayer, Quicktime and Windows Media Player 9. I need to get suggestions for software.
The only bug I've hit to date is trying to set up VersaMail. Its buggy, that's clear from all the forums. For me, it resets the device after it finishes syncing to my IMAP server. The "push" mail application on the Sidekick is clearly superior in most respects to VersaMail, from the interface to the fact that I don't have to "choose" how often to sync my mail, it just always arrives. Setting VersaMail to sync more often than once an hour causes it to warn you that you might shorten your battery life. Well, maybe that explains why the Treo lasts for days, and the Sidekick is lucky to last 36 hours.
My only other beef so far is with the SMS messaging. There is this confusion between email and SMS messaging, but I don't really "text" anyone (couldn't really on my Startac) but I use it heavily as a pager (I'm oncall at work) and my pages are all email... but I want to be able to respond from the phone, and the SMS client really doesn't want to respond correctly. It doesn't follow the Reply-To of the email, it doesn't let you edit the To address (unless you add a voice/image message.. but you have to add the voice/image attachment). On the Sidekick, I couldn't use the email as a pager, since I didn't want to be notified on every new message, and I can't use that on the Treo since VersaMail sucks and its not push. So, no replies from the phone.
I haven't been able to get bluetooth syncing to work, though I have used the infrared fairly easily. My laptop found the Treo, and my Treo found my laptop, but wouldn't sync. Dunno. I could have used the Treo DUN Hack when I was in a hotel in Tahoe without internet connectivity, but instead spent my time browsing the web via the Treo. I also found the pssh client to work amazingly well, and haven't had the annoying constantly dropping connections that I've had with the Sidekick's Terminal app.
Overall, I'm fairly happy. I haven't quite figured out how to answer the phone when its in my pocket (I keep answering it while getting it out, and then hanging up when I go to answer it). We'll see how it lasts. I don't think it will last 6 years...