Bottom line: this is the most impressive Windows Mobile device I've used, with great functionality and capability. Verizon's BroadbandAccess works great, and the built-in QWERTY keyboard is a terrific feature, but battery life could sure use some improvement.

First, the gross physical attributes. The converged-device market has started to coalesce into two form factors: sticks (like the SMT5600 and palmtop devices, which range from the small Treo to the big ol' HP 6315-- and this device. The XV6600 looks like a conventional PocketPC device, but when you slide it open that's when you really notice the difference. The screen is brilliant, large, and colorful; I think it's equal to the 6315's screen, although perhaps a little brighter in sunlight. Below the screen are the standard set of Pocket PC phone buttons: four hard buttons for Windows Mobile, plus red and green phone buttons.

The 6600's QWERTY keyboard slides out from beneath the screen. Greg Hughes called it a "pimple-style chicklet bubble layout", and sadly I have to agree-- the keys are little recessed circles, and there's very little tactile feedback when typing. The keyboard on the Treo is superior, although it's a good bit easier to enter text on the 6600 thanks to Windows Mobile's predictive-text engine. (There's also the fact that you can enter text using only the stylus on the 6600, which of course you can't do with the Treo).

Phone: the 6600 worked quite well as a cellphone. However, I had trouble making calls since there's no hard keyboard available for dialing-- unless you pull out the QWERTY, in which case there's no way to tell whether you're hitting the number keys or not. Many of the heavy Pocket PC phone users I know have Microsoft's Voice Command installed, and that's probably the best solution, but I didn't try it. Speaker and speakerphone volume were good.

Messaging: What can I say? It's Pocket Outlook, which worked fine over the air and when syncing with my desktop.

Synchronization: As with the SMT5600, I had a few minor problems with ActiveSync on the desktop, but those were easy to resolve. Over-the-air sync with EAS worked well, although I didn't use it much because of the phone's terrible battery life.

Bluetooth: This device has great Bluetooth support if you install the available update from Audiovox. I switched from the Jabra FreeSpeak 250 headset to the GN6210, which is essentially the same hardware; after installing the update, I was able to pair the headset and make and receive calls. Range wasn't that good; the manual suggests putting the phone on the same side of your body as the headset, and I found that if I didn't do that, I'd get some crackles and static.

Other: it's a darn good thing this unit has a replaceable battery, because the battery life is terrible. I got about a day per battery charge, and that's without using the device much as a phone at all. The ringer volume was too low; I missed several calls in airports, taxicabs, and other noisy environments. I never got used to the keyboard, which has basically no "feel" to it.

The one killer feature I haven't mentioned yet is Verizon's EVDO network, which offers up to 2Mbps of wireless service. It worked flawlessly in my tests in DC and Cincinnati (well, until my battery died). I didn't have the right cable to tether the 6600 and use it as a laptop data modem; if you've got Bluetooth in your laptop, the process is simpler-- in which case you'll find that Bluetooth is too slow to keep up with EVDO! (Instructions for tethering in USB and Bluetooth modes are here).

Bugs and annoyances: Verizon doesn't offer this phone with WiFi or a camera, even though other carriers (notably T-Mobile and Cingular) offer versions that have both. The phone would sometimes spontaneously reboot, and it kept bringing up a data connection even though I wasn't running any data applications (that I knew of, anyway).

Overall, I was impressed with the 6600. Even though it lacks WiFi, it's much better as a phone than the 6315, and it's more usable as a PDA than the 5600. However, the large size and poor battery life made it a poor fit for my use, and it's expensive to boot. However, the EVDO connectivity is a killer feature for mobile users, and once VZW and UTStarcom solve the battery life problem this will really be a contender.