I would call my change to Intel as big a jump as when I then went to a SSD.
From what to Intel?
If I am not mistaken, he was going from an AMD 8350 to a 3770K. Day to day tasks won't be the difference between night and day. When you get into specific programs that may take advantage of multiple cores, the Intel will perform better simply because the AMD doesn't have 8 true cores, and Hyperthreading is more substantial than splitting 4 cores into 8 like AMD does. Also, the Intel cores are more powerful and THAT will be noticeable when taxing all of them. If he was going from a dual or quad core AMD to this, yeah, it would be a hell of a difference. He had a solid system before the switch.
Well, let's see, the other CPU is AMD. I had/have two, a PhenomII X4 965 Black and a PhenomII X6 1055T, I still have both of them, wife uses the X4 965 system, the X6 is a backup machine.
The entire Intel experience compared to AMD is different. The Intel systems reboot faster, programs open faster, graphics render faster. This was with a spinner drive and a i5-2550K. To me after being on AMD systems for years it was a big kick in the ass by simply changing to Intel CPU and board.
It may be an exaggeration to say it was as big a difference as going to a SSD, but there definitely was a big noticeable faster change. My Intel and the wife's AMD system both have SSDs now and hers is still noticeably slower in general.