I can only give you my opinion about the Sony Vaio NW series because I got the Black Friday (NW265) version. The NW250 and NW280 versions should be much better than mine with the ATI discrete graphics and the Core2Duo processor. Try to avoid the Intel GMA 4500MHD integrated graphics.
Pros:
Keyboard is very comfortable to use and comparable to the MacBook Air
ATI HD 4570 discrete graphics (if you order from the Sony website)
Build quality is quite durable for an all plastic build
HDMI output
Blu-ray drive
Weighs at 6 pounds (portable enough to carry around campus)
Quite thin for a 15.5" laptop (1.2 inches thick)
Reasonably priced
Cons:
Battery life is quite low, 2-3 hours depending on your brightness
Speakers are weak with no bass, but that is expected from a laptop
Viewing angle is poor if viewed more than 45 degrees
My Photos: