Hey, i have played with three of these acer timeline machines as we have had them in work for a while now. Overall they seem great, good battery life and ultra sleek. They will not be the best for processing images as they are a single core, but use something similar to Hyper Threading to try and load ballance.
They generaly have 3 gb of ram and above, however i would be more likley to go for the 14" version for portability as this has the same processor as the 15 and runs at the same resolution.
What makes them different from the Atom processer is the amount of cache they have on the processor and the FSB that the processor runs at. Mega gains in comparison. To get the 8 hour claimed battery life you will have to dim the screen and maybe turn a few options off, but in the shop the other day a fully charged battery just playing a demo on loop, with the wireless off speakers on half and brightness set to half (i think) lasted 5 hours, which is pretty good going