Hi,
Received an E2 for Christmas and after researching both, exchanged it (plus $100) for a TX.
Factors for the TX:
1)-Faster processor: always good ;-)
2)-More on board memory (128 vs 32), although both are flash type (static RAM, no power required) & upgradable via SD card.
3)-Larger screen. This I have found to not be usable by some software, however, when it is, it is nice to be able to shrink the text entry area & is especially nice for pictures, as one may switch between portrait & landscape mode.
4)-Built-in WIFI. I am think the price of a WIFI card add-on will exceed the price of going to the TX.
5)Hopefully a slightly longer support cycle, as it is a newer product.
Against:
1)-Reportedly, less battery life.
2)-Obviously, greater $.
The software offerings appeared to be very similar, however, I am new to the PDA thing, it it would seem reasonable that the TX may have newer versions.
There may be other things, but these were what I considered material.