Why?It has nice modular cables 80 + bronze etcetc.
that's lovely but that is not how you judge a power supply, you judge it by independent reviews by professional sites with the right equipment to review it.
the issue is, two GTX660ti jan push 300w at peak. the rest of your system will add another 150w or so at peak
so while your PSU (its really a re-branded FSP 600w) can handle that kind of power output, pushing it to 75% peak constantly will increase heat output and can lessen its lifespan. So its not an ideal set up but it will work.