What I find interesting about Icasa's new licensing scheme is the way the fee of a point-to-point link is determined. It takes into account a few factors, such as frequency congestion, geographical area (a link in PTA costs ten times more than the same link in the middle of nowhere), frequency band, and channel size. But it absolutely does not take link throughput, modulation or ACM into account or XPIC.
If ICASA was really serious about efficient spectrum usage, surely they would reward an operator for using XPIC, which doubles the spectrum utilization for the link. Also, using 512 QAM is much more bandwidth efficient than using 4 QAM. And ACM makes links more dependable, though at a P_Tx cost to the operator.
By ignoring these ICASA really seems to have the money as first interest, rather than efficient spectrum use.