I got my Treo 750 this week as a replacement for a Blackberry 8700c, which I really liked. My company is heading away from BB and towards Windows Mobile technology, so here I am.I should say, too, that I've had pretty much every flavor of BB ever made, as well as an Ipaq, Treo 650, Cingular 8125 and many others. I had concluded that for a business user who needs 100% reliable e-mail, and uses the Internet and text messaging a fair amount, the BB 8700 was by far the most reliable way for me.So as I make the transition from 8700 to 750, here is my list (not too long at this point) of likes and dislikes:1. The Treo 750 comes new in the box without a holster, belt clip or carrying case of any kind. Unless you want to carry it in your pocket, automatically add $30 to the cost of the phone. Thanks, Cingular.2. Battery life is not good on the 750. I send and receive well over 100 e-mail messages a day, and my phone usage and Internet use varies. I could go two days without charging my BB, and even given my usage patterns, seldom ran out of battery power.Yesterday I flew from Chicago to Los Angeles and caught a connecting flight to Palm Springs. The point is, I had the 750 turned off for at least five hours during the day. I took it off the charger at about 6 a.m. Chicago time yesterday morning, and, even after being turned off for five hours, by 6 p.m. Chicago time yesterday afternoon the battery was almost dead.Buying a spare battery ($30 to $50) seems like a decent solution, but devices that charge the battery only (while it's not on the phone) are hard to find for this phone, and will cost around $50. So the logistics of getting two batteries recharged over night are not that simple - primarily because if you don't have a phone-independent battery charger, you will have to change the battery in the phone every day in order to get two batteries charged. And if you forget to charge the second one, you have potential problems the next day.As an alternative, you can keep the phone tethered to your computer or on the AC charger (have to have one or the other with you at all times) during the day, and/or buy a car charger, about $20 (if you'll be in the car). But if you're just out and about, battery life will be a significant issue for many.3. The display is pretty good. But brightness and readability of the screen while outside is an issue. Anyone who's had a BB 8700 knows how easy it is to read that screen outside. The Treo 750 takes a big step backward by comparison.4. Push e-mail reliability. For phones other than BBs, my company uses Good technology for interfacing with Outlook. Getting e-mail on my previous phones (Treo 650, Cingular 8125, etc.) that used Good Link was not reliable - I constantly had to use the "send/receive now" function to make sure my e-mail was up to date.So far so good with the 750. I have gotten my e-mails reliably so far - it seems as good as my 8700.5. Windows Mobile OS. One frequent complaint I hear about with Windows Mobile phones is that they lock up and need to be reset (soft or hard) frequently. Again, so far, so good for the 750. I did reset it yesterday because it went totally mute on me - no beeps, no notification sounds, no ringer on the phone! And no, I did not accidentally set the ringer switch to silent. After I reset it, all the sounds worked again. It's too early to tell whether this will be a persistent problem.That's about all that comes to mind right now. I hope this helps anyone make up their mind about moving to this phone, especially if you would be leaving a BB 8700 behind.So far, my regrets are minor, and I plan on learning to love this phone once I figure out how to deal with the battery problem. Good luck with yours.