Ordered an M17x R2 w/dual 5870m, Dell shipped me an M17x R3 w/single 6870m. What do I do?

Here is my scenario.  Last month I placed my order for an M17x R2 with i7 740QM, 2 X 5870m, 4GB DDR3, 1440 x 900 WLED, Anodized Aluminium (Red).  I expected to receive the order mid September.

This past Friday I find I have received my order.  Great!  When I open the package I find an M17x R3.  The first thing I notice is that this thing is all plastic.  I am disappointed and think, well maybe that is the only thing wrong with the order, so i turn on the laptop to go over the installed hardware.

This is what I find:

i7 2720QM 2.2 GHz (3.3 GHz Turbo Mode)

4GB 1333MHZ DDR3

1600 x 900 WLED

1GB GDDR5 AMD Radeon HD 6870m

320 GB Sata II

a $49 accidential insurance had been added to the invoice to make up the differance in price between the two laptops.

My big question is do I keep this or have Dell take it back?  Would it be worth keeping if Dell offered me a discount on the M17x R3?