I'm thinking about getting a Mini DisplayPort to HDMI adapter and running a cable from my Late 2013 27" iMac to my television. The main purpose of this would be to be able to play video games on my couch, running Steam on the iMac. Would there be much lag, in any of your esteemed opinions? Would there be any other considerations? Does the length and quality of the HDMI cable (or the adapter) matter much? Thanks for your time.