Some random musings…
Had a Samsung NC10 for about 18 months, it’s been well travelled, and still looks/performs as new. Had to get the screen fixed under warranty, and took about a week. It’s currently being used as a desktop with a keyboard/mouse/monitor. I have upgraded to 2GB RAM but sometimes use it for FEA, compiling code and other things it’s not meant for and it copes ok.
Girlfriend has an HP (I think) and the battery sticks out the back, making it awkward to transport. Not something you can see when they are in the shop with the battery not in it.
Generally they are all the same hardware so go for the one with the trackpad/keyboard you like the best and best battery life.
As much as I love Linux, I would suggest getting a Windows specced one, you can always add Linux later but it’s ££ to go the other way.
When/if mine dies I will replace it with the N220, or equivalent Samsung then. 10 hours claimed battery, and it looks good in terms of usability. It is £320 though 🙁