Hello, I have an iMac mid-2011 model 27". It works with b/g/n protocol and I want to upgrade it. I've found an AC Adapter (dual band-1900 Mbps) but wondering if I will see any difference in my network. Also I have an IPTV device which can connects to 2.4 GHz. If I hook up this adapter I'll be able to connect at 5GHz ?