welcome to the forums.
Why the reader? For me, it's a great way to get myself off of the computer or TV. I have known about Project Gutenberg for years, but outside of downloading "Devil's Dictionary" or reference material, I couldn't really get enjoyment from reading on the computer. The screen bothers me, at least enough that I couldn't imagine wanting to read an entire book in that manner.
as the other folks have stated, the e-ink screen is really great. Friends and folks at work may be a little put-off from the price tag at this point, but they all are amazed by the screen. I've heard people that speed-reading people aren't happy with the refresh time, but it is fine for me. Also, if someone expects to take a lot of PDF files and dump them on there, it may not be the right tool for them either. I do use PDF files, but they are a bit tricky. Some of them (simple ones?) you can just load, and they work fine. Some of them you need to run through a conversion tool (PDF Rasterfarian) , and some of them don't seem to work well at all without what I imagine would be a LOT of work (pdfs with non-white pages). The reader doesn't (at this point, but maybe never) have a search function, so I'd recommend books that you would read front-to-back like a novel, or a history book that you're reading front to back.
But as for my personal use, I have had a good time reading books I've found on several sites, including here, and I haven't even used Sony Connect yet because there are so many other books that I have found.