Should I get a desktop, or laptop?

Hey everyone.

I'm trying to decide whether I should buy a laptop or build a desktop. I want to be able to play games at mostly high settings (I can deal with some medium settings, v-sync and AA not being enabled and such) but I would like to be able to play games at mostly high settings @ 1366 x 768 resolution.

I'm always on my current laptop, but it's slowly dying, and I know I'm going to need a new computer soon (whether it be a laptop or desktop,) so maybe you guys can help me decide.

Here's the desktop I plan on building if I go with a desktop:
DESKTOP SPECS:
Processor: AMD FX-4170 Quad-Core @ 4.2GHz
Motherboard: ASUS AM3+ AMD 760G Motherboard
Graphics Card: ASUS Radeon HD 4850 512MB GDDR3
Storage: Seagate Barracuda Green 1.5TB 7200RPM HDD
Memory: G.SKILL Ripjaws 1066MHz 4GB (1x4GB) RAM
Power Supply: OCZ ModXStream Pro 700W Modular PSU
Chassis: Cooler Master HAF 912 Mid-Tower


PRICE: $551 APPROX. AFTER TAXES AND SHIPPING.


Here's the laptop I plan on getting if I go with a laptop:
LAPTOP SPECS:
Model: Samsung NP355V4-S01CA
Screen Size: 14"
Native Screen Resolution: 1366 x 768
Processor: AMD A10-4600M
Processor Cores: 4 Cores, 4 Threads
Processor Speed: 2.3GHz
Processor Cache: 4MB L2 Cache
HDD Capacity: 750GB
HDD Speed:5400RPM
RAM Size: 6GB
RAM Speed: 1600MHz
RAM Type: DDR3
Graphics Chipset: AMD Radeon HD 7660G + HD 7670M Dual Graphics
Video Memory: 1GB Dedicated
Video Type: Unknown (not sure if it's GDDR3 or GDDR5)
FREE COPY OF DIRT 3

PRICE: $740 APPROX. AFTER TAXES.