Tony - my law firm has switched to windows mobile devices for attorneys and tech staff. I ended up with the XV6700, but have worked extensively with the Treo 700w and 700wx. The 6700 (which I believe may have been discontinued already) was billed more toward tech users, has a larger screen, and leans more toward using the device as a pocket PC. The Treo has most of the same features, and to me its smaller screen is made up for in the fact that it fits so nicely in your hand. It feels more like a phone. Fits easily in your pocket too. We call the 6700 "the brick" for all the obvious reasons ... it's heavier, bulkier and you are just about required to have a case for it to carry it around. The Treo also comes with Voice Command (which, if you get one, you MUST activate - it's the coolest software ... lets you dial numbers hands-free by saying the number out loud, starts software on the device, etc.) I actually bought Voice Command for the 6700 because I like it so much. The screen, while small, is actually large enough to make out radar images, and I use it for mobile internet constantly. If I'm driving down the road and need directions, it's just as easy for me to pull mapquest or Google maps up on the device as it is to get out the GPS ... plus I have access to my web based email everywhere I go now.
Windows Mobile still has some bugs and it takes a while to catch on to some things ... for instance:
*when you close out of a program in windows mobile, you don't actually close it, you just send it to the background. The device thinks you might want it again soon or something. So you need to remember to do a soft-reset on your device EVERY day. Either that, or go into your settings and clear out all of the open applications periodically.
*Battery drain is a constant issue. You'll have to be prepared to keep the device charged in your car, at work, or at home whenever possible. You experience faster drain than Blackberry, cell phones, etc., because the device is computing all the time ... remember that it's as much a COMPUTER as as it is a phone. I keep surfing and game playing down unless I know I can recharge soon. And if I'm traveling for work, I take my charge cords with me in my carry-ons and then surf near outlets at airports, etc.
I have lots more info I can share on these, as I help train our attorneys how to use them (how to sync them properly, security measures, etc.) ... so feel free to ask anything you'd like to know.
For me, it's been a real boost up from the world of cell phones to the world of pocket PC's, but like I say ... there's still a ways to go before Windows Mobile truly gets all the kinks worked out.