I sometimes miss the simplicity of reading pbooks (lol I love that term), but I've been reading ebooks almost exclusively for a few years; my ereaders are easier to hold and weigh much less. I also love the idea of letters and words appearing in e-ink or digital form. It's so sci-fi-ish to me... I'm a geek. lol
EDIT: Oh, one more thing, I love the fact that you could sideload LOTS of ebooks into an ereader!