Still loving my 505, after about 10 months. (Had a 500 before that, which my SO is still loving!) I have purchased about 30 ebooks from Sony (incl. a few bundles) and have found tons of other free books (thanks largely to this site!).
Cool gadgetry and a bit of hacking aside, what I really love about my Reader is I have been reading for fun so much more now than in quite a long time. Through grade school until college, I always had a paperback with me, every day, and went through several books per week. Things changed over time, with college, other activities, and then the (regrettable?) onset of websurfing and a subsequent lowering of my reading attention span.
But now I'm back to getting immersed in lots of good old novels and stories. The convenience is great, and somehow the Reader just got me reading again! (I also do have a small pile of p-books on the reading list!)
Availability of ebooks from the local library is also a big plus, if I ever get through my current reading list!