I bought the 32GB wifi only version, since I'm rarely anywhere without wifi, and my phone has wifi hotspot on it anyway.
The selling features are the screen, the graphics, and the LTE, the last of which I didn't get. Oh and the camera.
Basically, going from an iPad 1 to this is well worth it, mostly for the screen. It's just really, really nice, and very functional for not only games and videos, but also reading. The new Kindle app looks fantastic, and I can actually see skipping a standalone Kindle now, for casual readers. Videos look awesome, especially anything in 720 or above.
The speed isn't anything special when compared to an iPad 2 (we've got lots of those floating around at work), and I suspect any gain from the quad core graphics and 1GB of RAM goes toward just powering the mammoth resolution.
The camera. Well, it is a lot better than the iPad 2's. And I didn't have any cameras at all on my own 1, so anythings better than nothing, at least for video conferencing. But realistically, how often do people plan on taking pictures with a 10" rectangle? Phones make sense, because their size makes them feel like a pseudo point and shoot anyway. But a tablet? I don't know, time will tell.
In terms of quality, if you've seen an iPhone 4 pic, this is basically the same thing. In fact, I think it's exactly the same camera with the added ability to shoot 1080p instead of 720p (though I suspect it's due to up scaling).
I paid for iMovie awhile ago, and it obviously didn't work on the 1 (just my iPhone 4), so it'll fun to futz with that.
What will be cool (especially once they update it) is my support client. With the resolution on this being higher than most computer screens, it'll be interesting to see how remote machine screens look. Citrix looks great, but I think it's still the same app version.
Like I said, it's more of the same. If you liked the 1 and 2, you'll like the "3" even more. If you're an unimaginative twit that thinks tablets are only good for solitaire, you can safely move along. I will say that working with a MIDI keyboard and the Apogee Jam, GarageBand moves like greased balls.
And the fact that they added MIDI piano roll editing makes the device extremely handy (more so than it already was) as a musical sketch pad. Add the Tascam iU2, and it can in many (not all) cases replace a laptop for field work/demos.
Have not gotten iPhoto yet; the reviews seem good, so for $5 it seems like its worth it.
Overall, I'm happy, impressed with the screen, but not exactly blown away. It is, after all, just an evolved iPad I already had. I wasn't expecting to be blown away though.
Oh almost forgot: Diet Siri, the transcriber. It shows up (as far as I can tell, anyway) everywhere a keyboard does, and works very, very well. In comparison to Dragon and Vlingo, it simply blows them away.
It's also significantly better than Android (at least 2.3. I've not used much in the way of ICS devices).