I see....I've never researched this part of the connection. The reason I don't like internal PCI cards over USB is because I have seen them drop the connection time and time again, sometimes won't connect- so it's more of a connection standpoint than anything. I can see where the 2-6C could cause issues, especially in gaming rigs.
As for the USB, I've never seen an issue with them obtaining a connection, and keeping it longer than a PCI. Although, we are dealing with wireless, and many fators come into play, ie distance, interfearence, walls, floors, metal, etc. For someone relatively new, or non-technical, I recommend USB over PCI for the connection reason, plus ease of use. I never knew about the heat issue it could potentially cause- that's good info.