Soldato
Personally going from a Q6600 set up to an i5 2500k, I noticed a considerable difference.
Things just seem snapper.
That being said I upgraded to an SSD at the same time, but when I have run a VM of a mechanical drive, and run Win 7 off a Mechanical drive (didn't get to play with that set up long) it just feels better.
Your personal miles may vary but I was more then happy to go to the i5.
It's snappier due to the SSD you have. For gaming he'll not notice much difference to be worth the outlay for new cpu, mobo, ram, cooler.
My card (570) and my C2Q q9550 are still gaming perfectly fine and I see no need to upgrade anything for a while to come. I think when it comes to encoding I will still be able to handle the extra 20 second wait for the 9550 to do what the sandy chips can do quicker. Lets be honest how many of us encode that much? it's mostly all gaming for the majority of us reading these forums. Not all I know, but most of us will be for gaming and browsing online and for that reason I'd say he should drop in a new graphics card and overclock the CPU instead.