I think FRC is not for investing, because it's designed just for trade purpose. Its price does not obey the natural rule. In this sense, I think PPC is better for invest in comparison.
Better for whom? The investor/lender would indeed be 'better' off with the 'hard' currency with high interst, the borrower will be better with the lower interest FRC. As their will be more investment under a low interest currency then a high one and higher investment is better for general prosperity FRC is better period.