Yea, with the monitors, i'm more talking hypothetically about stressing the system. As for my choice to go with the six cores, I wanted to be future proofed for several years, and decided to take the calculated gamble that games will start heavily utilizing all available cores and threads in the near future. And in your case its definitely fine that you went your route as well. If you have budget, the z77 and ivy core is still a powerful combination.

I play huge map, 22 civ, modded games in Civ5. On my q6600/6950 system it got laggy after getting late in the game, now, absolutely none. That is where the extra processing power of the current CPU's shine, your ivy/ssd/ram heavy combo will do nicely. I doubt it taxes your system.

Here's the 670 for $279.99 after MIR (sale tax in CA) if anyone is interested.

http://www.techbargains.com/news_displayItem.cfm/333708

I would have done this except for the tax makes it $304.49 for me.