Hey guys, I currently have 2 MSI R7870 Twin Frozr Ghz Edition in crossfire. I want to know if its worth upgrading to other cards like a gtx titan, gtx 690, gtx 780 or the 7990. I currently play on a 1920x1080 resolution and can play pretty much any game on their highest settings but I want to have my pc ready for next generation games. Should I stick with the 2 7870s or get something better?