I still own my 505, allthough I passed it on to my wife. That was when I bought my 600. I do like the 600's capabilities, but the 505's screen is just superior.
I got my 600 now for reading novels and similar stuff only. Although I'm not an an apple fan (my ipod didn't connect to my pc at the time, so I returned it and bought a zune later) I added an ipad to my collection. I wouldn't use it for novels, but it's cool for technical stuff. And hey, it's plain awesome to sit on the balcony writing this post. Wouldn't have done that with my laptop.
I'd say I go with a modifcation of apples app-slogan: There's a device for that, and that...
