no contest the GTX 770 is the better choice for a few reasons.
the GTX 670 is incapable of utilizing 4GB's of VRAM, no strong enough, it would take Tri-SLi to get any benefit @ 5760 x 1080p resolution or higher.
I'm not sure the GTX 770 and push 4GB's either but reviews on that are coming out and I hope it can.
for now the 2GB cards have been proven to be enough and actually a few frames faster in some benches over the 4GB versions.
and pricing, the GTX 770 is $399+ while last I checked the GTX 670 was still $350+, that alone makes no sense..