Help choosing between dell studio 15 or dell dell studio xps 16?

So here is the deal. In the fall I am going to be attending college and will be studying engineering. I finally feel as if I have found two quality computers that i believe can get the job done for me ( running all the sorts of engineering programs along with multitasking), but I am having a terrible time select one. If I could get any insight out there it would be greatly appreciated....

Here are the Specs ..
Dell Studio 15

--PROCESSORIntel® Core™ 2 Duo T9600 (2.8GHz/1066Mhz FSB/6MB cache)
--WARRANTY AND SERVICE3Yr Ltd Hardware Warranty, InHome Service after Remote Diagnosisedit
--HD DISPLAY15.6" Full High Definition (1080p) High Brightness LED Display with TrueLife™ and Camera/Facial Recoedit
--MEMORY4GB Shared Dual Channel DDR2 at 800MHzedit
--HARD DRIVESize: 500GB SATA Hard Drive (5400RPM)
--VIDEO CARD512MB ATI Mobility Radeon HD 4570
--INTERNAL OPTICAL DRIVE8X Slot Load Super Multi (DL DVD+/-R Drive + RAM support)
--WIRELESS CARDSDell Wireless 1397 802.11g Half Mini-Card
--BATTERY OPTIONS85 WHr Lithium Ion Battery (9 cell)
--SOUND OPTIONSSoundblaster X-Fi Hi Def Audio - Software Enabled
--KEYBOARDBack-lit Keyboard

OR

Dell Studio XPS 16
--PROCESSORIntel® Core™ 2 Duo T9550 (6MB cache/2.66GHz/1066Mhz FSB)
--WARRANTY AND SERVICE1Yr Ltd Hardware Warranty, InHome Service after Remote Diagnosis
--HD DISPLAYEdge-to-Edge FHD Widescreen 15.6 inch WLED LCD (1920x1080) W/2.0 MP
--MEMORY4GB Dual Channel DDR3 SDRAM at 1067MHz (2 Dimms)
--HARD DRIVE500GB 7200 RPM SATA Hard Drive
--INTERNAL OPTICAL DRIVE8X DVD+/- RW(DVD/CD read/write) Slot Load Drive
--VIDEO CARDATI Mobility RADEON™ HD 4670 – 1GB
--WIRELESS CARDSIntel® 5100 WLAN Wireless-N (1x2) Half Mini Cardedit
--SOUND OPTIONSSoundblaster X-Fi Hi Def Audio - Software Enabled

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