I initially fell in love with the Kindle when I got it from my brother, and then when I bought my own fell out of love, then back in love. It took me a while to get used to the difference in flipping through (highlighting helps!) and the different way it fits in my hand. Now I so dislike the idea of pbooks.

My library has a decent selection of stuff online, which really helped. I'd just request them for when they're available, and get a notice in my inbox. It made getting books I really wanted to read easy, and checking out stuff I'm not so sure about. Being able to try all different kinds of things without the commitment of going to the library, checking out a heavy stack, and then having to bring them back again and potentially not even like them!

For getting an upgrade, I don't know if it's this easy at every store, but I bought a Nook at Barnes and Noble and returned it a week or two later when I discovered it didn't save my notes the way I needed them. Full refund, no questions asked. I'm not sure I'd recommend that for a trial, but some stores have friendlier return policies if you're worried about making a big jump.