I have a T/X, but probably not for the same uses as most of you.
I was a PDA guy, once. I had a
Sharp SE-500 back when the Palm Pilot Professional was becoming the emergent PDA. It had a geeky flip+swivel cover that kinda went click-clack-click whenever you opened or closed it. It was fun.
Over the years that evolved into a Handspring Visor, to a Sony CLIE, and ultimately I found myself not using a PDA so much. You know why? My cell phone! Back when I was a PDA geek I had a Nokia 5190 cell phone which was too big to fit in a pocket, so I always had my phone clipped to my belt. Now that my phone is pocket-sized, I have the phone and keys in one pocket, wallet and coins in another... and there's really no comfortable place to put a PDA (or an iPod, for that matter).
So I've basically learned to live without a PDA, and I sold the Sony CLIE.
That said, I did buy a Palm T/X at a good price, refurbished, about a year ago. I use it to keep tabs on
geocaches, so I essentially use it as an offline web browser. I also love a good game of AcidSolitaire or Bejeweled -- great for bus or car rides or long waits at the doctor's office.
I like that the PDA has NVRAM so that settings and apps aren't lost when the battery dies. Those early PDA's used AAA batteries that lasted a month at a time, but today with color screens and wireless they only last a few days between charges. Losing all your data due to a dead battery was annoying and was one of the reasons I learned to be less dependent on my PDA data, and, eventually, not dependent on a PDA at all.
The WiFi on the T/X is a cute feature, but in practice I hardly use it. Like Steve Jobs said, you're browsing a mini-internet, and it's slower to boot. For me, the novelty of being able to check Gmail from my pocket was just that, a novelty. I have no REAL need to have Internet access "everywhere". I have found the WiFi reception to be rather weak, and it doesn't even work with my Apple Airport Express for some reason.
I do like the big screen of the T/X, great for reading e-books.
Overall I'd say, it's a good little unit, and if it meets your needs, all the better. But for me, if it weren't for the one redeeming use (storage of geocache data), I wouldn't have bought it, as I've learned to live without PDA's altogether.