Hi I am a 1215B user here for about 3 months. Just sharing and to do a simple review of this ultrabook/netbook/ultra-laptop. Having used 10" netbook, business laptop (such as lenovo X210) and 14" laptop so I am doing comparison.
CPU performance - The E350 chip is good and fast. Mine is 4GB RAM. Tried multi-task and found that max I can have is 4 windows open simultaneously (video, surf net and downloading, edit docs and copying files) before u see any significant lag. Of course still lose to those i5 i7 intel lah, but comparable to i3 in my opinion.
Battery life - approx 6hrs on power saving mode. If using it to work and watch video for full duration, i estimate can last 5 hrs max. Much better than the other laptops i have used.
Weight - Light. I think its 1.2kg? Only a bit heavier than the 10.1" netbooks. Can fit into those tablet messenger bag. I using a vertical messenger bag meant for 10.1" tablets and it just fits inside nicely.
Screen size and Graphics - 12.1 or 13.1 if you want portability and not squinting your eyes at the same time. 11.6 i find too small for watching video or play game or do work. Graphics is good. Played games L4D2 and CS source normal setting. A bit of lag but bearable. Played video and also connected to HD TV using HDMI, both very good and clear.
Build Quality - the touchpad problem. It was a problem when i bought it a few months ago and I had to go down to the service centre to change. Troublesome even though it took less than 10 mins to rectify it at the centre. The keyboard is nicely laid out although i had some issues with the right shift and enter button which were quite small. Cover is matt black (i think also got glossy) and inside screen border is glossy. I find both are finger print and dust magnet.
Others (pre-installed apps, connectivity, camera, fan noise, heat etc) - Most of the pre-installed app I seldom use. Webcam is ok. Noise and heat level is fantastic, very low noise and i dont find it hot even on for 2 hrs in non-aircon room. There are 3 usb port, 1 of which is the usb 3.0. Adequate for me. The sound is decent, using realtek hd audio. Plug in headphone always got some screen popout to ask me configure sound settings, but i guess that can be turned off. There is always auto update notification when i turn on the laptop, then will tell me its the latest after checking. Dono if can disable that function or not as i find sometimes quite irritating. I believe that is to update the Nvdia drivers.
Overall i am very satisfied with the 1215B. Was considering the dm1 also but screen size 11.6" a bit small for me (as mentioned earlier).
Forgive me for some of the amateurish expressions as i not computer expert and above are my views only. Hopefully this review is useful for those who considering to buy this laptop.