Pros: Long battery life, bright and crisp screen, easy to use
Cons: Proprietary charger, only reads small SD cards, glitchy syncing, difficult to set up with Blackberries
The bottom line: Good for somewhat tech-savvy people looking for an all-purpose PDA.
The Tungsten E2 is great for: Reading ebooks, keeping checklists, scheduling tasks and appointments, jotting down quick notes, playing games
The Tungsten E2 is acceptable for: Watching videos, listening to music (with headphones), typing documents (with an IR or Bluetooth keyboard), viewing photos
The Tungsten E2 is sub-par at: Anything involving an internet connection, regular hotsyncing, storing much data on-the-go

I purchased the E2 to be used primarily as an organizational tool, a replacement for sticky notes and to-do lists and a way to remember appointments and events. The included software is serviceable for this, if not incredibly intuitive, and I was able to easily find a number of free programs to add to the functionality. Using the stylus to write is easy, but somewhat slow and inaccurate even after you get the hang of it, so you won't want to write long things that way.

I've now owned it for over six months, and I still find myself with paper lists...but unexpectedly, the E2 has become my favorite portable entertainment device. It has replaced the heavy books I used to carry around to read on the bus, and the many games available (both free and not) have kept me entertained when I've been stuck in a long line, waiting at the bus stop, or killing time on the phone while on hold. It even does a fair job of playing videos, though I had to find third-party software to convert them properly.

All this media and game use brings me to a couple of issues I've had with the E2 -- transferring data and having storage space. The hotsync feature is temperamental at best, failing nearly half the time for me, often for no apparent reason. I would have preferred a simple drag-and-drop interface to the multiple programs installed to interface with the E2. I also found out the hard way that the E2 will not read any SD card over 1GB, which for me decreases its usefulness (for instance, I can't pop a larger card out of my laptop or other peripheral device to transfer data; I have to either go through a computer or attempt to send via bluetooth, which for some devices like Blackberries, is difficult or impossible to set up properly).

Overall this is an excellent tool for the casual user. There are enough programs and peripherals to make it very customizable, and the general usability is good. It's suitable for someone who doesn't need a high-powered executive-level organizational tool, but who is tech-savvy enough to tinker with software and settings to get it to do what they want.