Just with a quick look at the Dell US site, here are a few things I noticed:
Studio XPS 16:
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- Up to 8 GB of 1333 MHz RAM
- ATI HD 4670 1 GB GPU
- Up to Core i7-820QM (1.73-3.06 GHz)
- Up to 500 GB of hard drive space
- 1920x1080 resolution monitor (15.6")
- Offers Blu-ray optical drive
- No touch-screen
versus...
Studio 17:
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- Up to 4 GB of 1333 MHz RAM
- Only Intel HD Graphics
- Up to Core i5-520M (2.4-2.93 GHz)
- Up to 1 TB of hard drive space
- 1600x900 monitor (17")
- No Blu-ray
- Multi-touch technology
If you don't mind not having a 17" laptop, you should look at the Studio 15. It's pretty similar to the Studio XPS 16.