I'm running a an I7 2700K on an ASUS P8Z68ZPro-Gen3 at 4.8 Ghz 24/7 and up to 5.2 Ghz with 16GB's of Samsung MV-3V4G3D-US_DDR3 at 9-9-9-24 -1T at 1.35mv at 1866Mhz with 2 OEM 290X's in XF. PCU and GPU's under water and a 1050 Watt XFX BFEX PSU - Do I want to upgrade "HELL NO" at this point.
Gotta say that AMD X's 8960 twitches me but can't justify the expense for the slight increase in performance.
May be something in the future will eventually make me pull the trigger - AGAIN and my system is 4 to 3 years old.
Seems to me DeskTop PC's are not going anywhere.
Other then that spew, I gotta clean the Platform and change out a few dead Rad Fans, flush and change the fluid - Never been over 70C under full load.
My advise to you is keep your I5 2500K and wait as you are Fast enough ;o)
-----------------------------
PS: If you want a little more Boost sell your I5 2500K and buy a used I7 2700K for under $300 and implement 8 Cores through Hyper Threading.
No matter what Intel Enthusiasts say about the I7 2700K. It's HOT CHIP for the money right now for our older MB's.
Granted Sandy Bridge is somewhat power hungry an I would not recommend anything less then an 850W PSU if running SLI or CF.
A 750W PSU will do if your running a single GPU and still OC.
Although power hungry, the I7 2700K is a Top Binned Intel Sandy Bridge I7 2600K CPU and considered a Monster even by to days standard.
Not that many where made but it's a last chance to buy as prices are going up on this CPU.
Sorry but I would ick a Binned Sandy Bridge over the Hot Tempered Haswell.