I just upgraded to the latest Ivy Bridge. I pretty happy with it. Multi tasking seems much smoother now things seem to load up just hair faster. Haven't had a chance to fire up a game yet since it was late by the time I finished. I only upgraded the CPU, Motherboard and Ram. Specs listed below.
I had Intel Core 2 duo Conroe 3.0g, 4G Ram, and ASUS P5n-e Sli MB. And now have I5 3570K, G.Skill 8G ram, ASUS P8Z77 MB. The new mother board has all kinds of overclocking features, which I haven't tried. But I'm not really into overclocking so I probably won't mess with that.
I'll definitely get an SSD in the future. I didn't really have any issues just plugging in my hdd with the existing Windows 7 install, it did seem to mess up my Nvidia driver
and Norton AV and some other not that important programs. But just reinstalled those and all is good. I thought I was going to have to do repair install, but I was able to just load all the new drivers
and activate windows. Overall went smooth.
One issue I had, that was I neglected to check if it had IDE connections, and it does not. So I had to do away with my Win XP drive and one of my optical drives. No big deal though since I almost never ran the xp anymore and the optical drive was just a hold over from other pc builds.