For me there's 2 sizes of mobile computing, either it fits in my pocket, or it doesn't. If it doesn't fit in my pocket then I'm going to have to cary it around in some kind of bag. Honestly at that point, a couple inches/pounds really doesn't make much of a difference--I would rather have a full-featured laptop.
I agree here. Which is why I have a Samsung i760 instead of an ASUS Eee PC. I saw the Eee at Best Buy for $200 and I considered it but then I realized it didn't offer me anything over my i760 and I couldn't fit it in my pocket.