Troy, two well-positioned subs(typically at the mid-points of the opposite side walls, or of the front and back wall, or in diagonally opposite corners)can help lessen the effect of room modes and result in smoother bass.
Your main question, however is whether a so-called "7.2" receiver has significant benefits. The first point is that there's no such thing as a 7.2 channel receiver or a 7.2 channel format. There's only a single .1 low frequency channel, and having two outputs for that channel rather than one(in effect, an internal Y adapter)is at most a minor convenience since an external Y isn't needed. The 6007 sends the same bass signals out through each of the two outputs and they can't be calibrated for loudness and delay separately, as a very few receivers can do(which still doesn't create .2 channels, just independently calibrated .1 content).
The 6007's "7.2" label should therefore have little or no weight in your decision.
