Actually, I don't think there's any native 7.1 material out there. Some 6.1 and a boat load of 5.1 but no 7.1 as far as I know.

Plus, it doesn't magically turn two channel into 5.1 channels. It "interpolates" sounds and assigns them to different channels according to some algorithm. IOW, it's an artificial construct.

But, ultimately, it wouldn't be a valid reason for me to upgrade.