For a mere $500 you can now have the tip top of the Treo line, the 700wx.

The 700wx is an upgrade to the 700w, the Windows Mobile-based version of the Treo. And let's cut to the chase about why you might prefer it to the standard 700w. Here's what's new or upgraded:

• Size, shape, and memory are all identical to the 700w. (Some websites are reporting that the 700wx has more RAM than the 700w, but they both offer 128MB. The 700wx does have more RAM available to programs, which some sources say results in a slight to moderate increase in application responsiveness.)
• The 700wx supports dial-up networking, which the 700w does not. In other words, you can use it as a modem for your laptop or PC when you're on the road. Since it supports EV-DO high-speed wireless, this can be a major plus.
• The 700wx operating system is slightly tweaked from the 700w, fixing some minor problems that 700w users have complained about.
• The 700wx (Sprint only) costs $499. The 700w (Verizon only) costs $299.

Watch that last step; it's a doozy. Despite early hopes, there's no GPS, no major RAM upgrade, and not even a screen resolution upgrade on the 700wx. $200 for dial-up networking and a little faster response time? That's frightening.

Also, don't expect much service difference between Verizon and Sprint. Since both Verizon and Sprint networks use CDMA/EV-DO service, there's no real difference in the type and quality of calls. If you're already using a Treo on Verizon, the experience will probably be about the same on Sprint.

My recommendation? If you're a Sprint user, this is the only way to get a Windows Mobile Treo, and it's only $100 more than the 700p, which Sprint also offers. If the OS is worth that much to you, go for the new one. But if you're on a different network and already have the 700w, you definitely won't want to break your current contract so you can get what amounts to a modest upgrade at best. I'd expect prices to fall rapidly over the next six months, too, so hang in there.

UPDATE: I finally got my hands on a Treo 700wx to do some hands-on testing and it does indeed respond faster than the 700w, but there's a catch: I got about 4 hours, 45 minutes of talk time until the battery died with the 700wx, vs. 5 hours, 30 minutes with the 700w. Not a huge difference, but one worth noting if you're considering the switch.