For $1500 desktop (i'm assuming that it's spent ONLY on the hardware and not keyboards, monitors, etc) you can definitely get a GTX 670 and a i7-3770k...
But if you're looking for bang for the buck, GTX 660 TI is the way to go. The factory overclocked ones will usually match a stock GTX 670's performance.
But ya. like the reviews say: GTX 660 ti costs 25% less than GTX 670 but only takes a 10-20% hit in performance.