Lenovo U series vs X series

I was looking to get an affordable (less then 1000$) laptop for school and small gaming (no high graphics required, I would like to have the option of playing starcraft or diablo3 on low settings). I need something that has a long battery life as well(this is very important) and was wondering weather to pick the lenovo thinkpad X series or ideapad U series. I wanted to know what the main differences were because I here that thinkpads are so much better? The Ideapad seems to beet the thinkpad series by a lot, so what would be a better choice? And I don't care about weight

I am from Canada and any links to websites which sells these computer for a low price would be appreciated.

X220 series (for the same price) had the following specs- Intel Core i5-2520M Processor (2.50GHz, 3M Cache with Turbo Boost up to 3.20GHz, 12.5" HD (1366x768) LED Backlit Display, Mobile Broadband Ready, 2x2 Antenna, ntel HD Graphics 3000 processor graphics with dynamic frequency, 4 GB PC3-10600 DDR3 SDRAM 1333MHz SODIMM Memory (1 DIMM, 320GB Hard Disk Drive, 7200rpm, 6 Cell Battery.

U400 series has the following specs.
Part number: 09932PU
2nd generation Intel Core i7-2620M Processor( 2.70GHz 1333MHz 4MB)
Genuine Windows 7 Home Premium 64
AMD Radeon HD 6470M 1GB
8.0GB PC3-10600 DDR3 SDRAM 1333 MHz
14.0" HD Glossy with integrated camera 1366x768
Industry Standard Multi-touch 2 button touchpad
500GB 7200
DVD Recordable
4 Cell Li-Polymer
Intel 1030 BGN+BT Wireless
One year
Notebook