I got the 32GB, WiFi+3G model when I was investigating options for my mom.

I haven't done much serious with it. It's neat, but has several limitations.

1) The screen is great, but gets smudges and fingerprints easily (I have a clear film cover on mine) since that's how you interact with it.

2) At about 1.5 pounds, it's light for a PC and has great battery life, but heavy for a book or bookreader. I don't know if I would want to hold it up in a lap for hours for reading. Craning ones neck for hours while keeping it flat on a table isn't too good, either.

3) I've downloaded a bunch of free books from the Apps store. The text is clear and the color pictures are nice. I haven't read enough to know how good it is at keeping bookmarks and the like, eyestrain issues, etc.

4) I'd be careful about understanding DRM issues before committing to a particular reader. Amazon has famously "recalled" books (and given credit back) for ebooks they sold that they didn't have rights to. Unless it's a truly free book, you probably don't "own" it. There may be limits on how many machines you can transfer it to, etc. There are reader apps for many platforms, but that doesn't necessarily mean you can copy DRM books to any of them that you want.

5) The Osmos game is astounding.

As Mike said, the iPad has the advantage of also being a PC. But it has very limited RAM and can be network intensive if you want to jump around the web a lot with it. It doesn't have Flash (and the work-arounds don't (yet/ever?) work for Flash Apps like games). I don't know how good the multitasking is (I haven't updated to the latest iOS yet), but it's generally surprisingly snappy. The 3G service I have is $25 a month, IIRC. It's handy when you're in the sticks and away from a WiFi access point, but I rarely use it except on trips. (It would be great if the 3G was ala-carte... :-/)

It's probably best to play with them in a store if you can. If you're just wanting a bookreader, a Kindle or Nook is probably a better choice (much lighter, much cheaper). If you want an all-in-one, the iPad is about the only choice at the moment.

HTH a little.

Cheers,
Scott.