I have asked around about which memory to get. I haven't had a satisfying answer. What I have heard so far is that it really doesn't make a difference. But if that is so, why do the manufacturers bother increasing the speed of their memory?

Where would the different memory speed make a difference? How big an improvement is the faster memory?

Whilst on the topic, would it matter whether the memory were Kingston Hyper-X Genesis or Samsung? I don't know in what significant way the actual manufacturer makes a difference. As far as I know, memory is guaranteed for life these days, isn't it?

The CPU would be a Intel® Core™i7 Quad Core Mobile Processor i7-3610QM (2.30GHz) 6MB.