I used to (mine was the i7), until i just designed my current FSX rig. It ran decent, frames in the 20-30 range in dense airports with REX UTX GEX PMDG LDS etc... With dual monitors btw... i had a 27" led cinema display hooked up to it. at level flight in cruise altitudes, i was seeing 60 frames. Not too bad, but not like what i get now :)