Yes, that makes sense.

I was planning of perhaps getting an Alienware M17x R3 laptop, and in their configuration they also have the higher clocked RAM.

CPU would be an i7-2760QM, but then again, that's 171€ more than for the i7-2670QM, and I don't even know if you would notice that much performance increase, what do you think?

GPU you can chose between the ATI HD6990 or the nVidia GTX580, same price, and I guess also same performance. I would go for the ATI.

The price for the 8GB 1.333MHz clocked RAM is 126€, and for the 8GB 1.600MHz clocked RAM is 192€.