Travel Technology - Seeking feedback: Smartphone to replace Treo 650

I'm continually impressed by the knowledge and advice around here, and I thought I'd solicit a little feedback about smartphones.

I've been the proud owner of a Treo 650 for going on three years now, and I can't say enough good things about the phone. I really love it. But it's time to start thinking about a replacement, and I'd really appreciate advice about possible alternatives.

Background: I use my phone a lot and the internet more. I really appreciate the intuitive nature of the Palm OS, and I rely on a number of 3rd party apps. I may be an outlier, but I dont' mind the size or weight of the 650, though I have swapped in a low-profile antenna. I carry it in my pocket, and I'd do the same with a new phone.

My must haves: touchscreen, full keyboard (no iphone, sorry), either Palm OS or Windows Mobile (more on this below), removable battery. I'd also like a dedicated mute switch, GSM, and faster web access. I know some of this is determined by carrier.

At the moment I'm leaning toward a newer Treo, but I'll admit it's hard to get excited about that option. Palm just hasn't kept up with the rest of the pack in some areas (wifi, GPS, etc). I played around with the Tilt recently, and it's not bad. Felt a little flimsy, and no dedicated mute switch (that I could see). Same goes for the T-mobile thing that looks like the tilt.

Here are my questions:

- First of all, what models you recommend?
- Impressions of WM6/6.1? I like the Palm OS, but I'm open to switching. I tend to hear little enthusiasm for WM6, however, and it seems like we're a ways off from 7.
- WM6 seemed sluggish on the phone I tested in-store. Is that typical?
- Are there any dual GSM/CDMA smartphones out there? I'd like GSM to be able to use the phone in Europe, but I suppose I could get a separate cell phone for overseas use. (I'd appreciate any insight in this area.)
- Are there any rumors I've missed about forthcoming smartphones that are worth waiting for? I could hold off 3-6 months to switch, I think.
- For anyone that moved from a Treo to another brand of smartphone, I'd really value your opinion. If your new phone has a hidden/sliding keyboard, did you mind that change? How about from Palm OS to WM?

Thanks in advance, everyone. Depending on feedback and interest, I'd be happy to turn this thread into a smartphone master thread, of sorts, to make it more of a FT resource.

Lots of questions... I'll see if I can answer as many as possible...

1) WM6/6.1 is decent. It's not where it should be, but it certainly is better than previous versions. You'll need to invest a little in some better software to replace some of the stuff on WM (like the browser)

2) If it seemed sluggish in store then it's probbaly because people had been opening tons of applications on it when playing with it. For normal use I'd suggest getting a memory manager and keeping an eye on open programs

3) There are some CDMA/GSM phones (like the Samsung ACE on Sprint) but they don't have a touchscreen.

4) There are some new phones on the way (as usual). The Palm Treo 800W is one example. It'll be out on Sprint first and will have WiFi, GPS and EVDO Revision A (nice and fast data). But it will have the same form factor as all other Treo's, so that may be too boring for you.

5) The learning curve isn't too steep from Palm to WM, but it'll still take a few days to get used to it.