QUOTE(eugenelimys @ Dec 24 2012, 07:30 PM)
RX17 is dual GPU while M17x is single GPU.
So, battery life M17x is the clear winner. dual 7970 can last around 2-2.5hours while M17x can last around 4 hours with single battery.

Though, 2 batteries. Not sure. Maybe can do? Though not recommended as I will taking down notes in class. Lol..
Ah Okay, I got it now. The RX17 comes with a dual GPU.
Hmm..., you can always choose RS17. I know RS17 has issue with AMD Enduro stuff but you can always choose the GTX680M, unless it is necessary for you to go for AMD? As far as I know Nvidia Optimus has been around for quite some time already compared to AMD Enduro. So, I dare enough to say that Nvidia Optimus technology is more mature than AMD Enduro technology, no?
Besides GTX680M, you can still have a LCD matte screen. For some people, they might have issue with reflective (Glossy) screen, therefore matte screen is good option. But I think for portability and at the same time for the power, RS15 would do fine because you can always get rid of the dvd rom and replace it with another HDD. Rarely using dvd rom these days.
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Here is what I had configured RS17 for your reference.
ILLEGEAR RS-17 Promotion
Details :
Display: 17.3" Full HD LED-Backlit Display with Matte Finished Surface (1920 x 1080)
Perfect Screen Display: Professional Color Calibration [FREE]
Processor: 3rd Generation Intel® Core™ i7-3630QM Processor
Graphics Card: 4GB GDDR5 Nvidia GeForce GTX 680M GPU with Optimus / Embedded Intel HD Graphics
Thermal Compound: IC Diamond Thermal Compound - CPU + GPU [FREE]
RAM: 16GB Dual Channel DDR3 SDRAM at 1600MHz - 2 X 8GB (FREE)
RAID Storage Options: Non-RAID Storage
Primary Hard Disk Drive: Western Digital Scorpio Black 500GB 7200rpm SATA2 Hard Drive (FREE)
2nd Hard Disk Drive: None
mSATA SSD Drive: None
Optical Drive Bay: 8X DVD±R/RW/4X +DL Super-Multi Drive & Software
Wireless Network Card: Killerâ„¢ Wireless-N 1202 802.11 A/B/G/N Wireless LAN + Bluetooth 4.0 Combo Module
Operating System: Genuine MS Windows® 8 64-Bit Edition
Warranty: ILLEGEAR 2 Year Limited Warranty
RM 7214