The return is not taxed, but I would just mention again that it's an inverted RRSP. So the return is not taxed on RRSPs either. It's taxed when you cash it at the end, but you get a deduction at the beginning that you don't get with a TFSA. So it's just inverting the two.
If you don't like TFSAs, you shouldn't like RRSPs either. They are just the same tool, but inverted.