There’s a very important distinction to be made here: this model uses a solid state drive, not a hard drive. The solid state drive, or SSD, doesn’t use a traditional SATA connector or IDE. It is more of a card, and I believe it is mini-PCI, though I could be mistaken. You can upgrade the SSD, but it will cost you: a 32GB SSD runs almost the cost of this netbook. There doesn’t appear to be space for a hard drive (I took mine apart when I first got it) and there is definitely not a connection for it. I’m not saying it is impossible, just unlikely.
I have this exact model, and everything is great, except the SSD is slow like whoa.
I run Ubuntu on it because the Xandros distro that came with it is fairly crappy. Ubuntu 9.04 has a couple of quirks on this hardware, one of them being that you cannot toggle the wireless, another being that you cannot toggle the tap-to-click on the touchpad, another that the wireless is sometimes a bit unstable, as well as there is a bug in the sound driver in which when the audio is muted, audio playback causes a crackle from the speakers. This is not the Apple user’s portable. It does not always just work.
As a pro, though, you get a 45 second boot time to a usable, fully-loaded desktop! Much nicer than my laptop.
Why you should get this: lightweight, 2.5hr battery life is better than your old laptop, portable, given the right distro–fast boot times
Why you should not get this: keyboard is smaller than a normal one and is harder to type on, processor does not perform like a 1.6GHz of any other model, not really useful for anything beyond internet browsing/email checking/taking notes in class. Do not buy expecting it to run games. It can barely handle Flash. Don’t put Windows on this thing.
That said, if you use it like I do (browsing, note-taking) you will probably like it. It definitely is a fun toy.