UNprofitable PoW
This reminded me to tell that Iota shouldn't be mentioned together with UNprofitable PoW in the same phrase. The PoW is not subsidized (like 25 BTC in Bitcoin or fees) but it can still be profitable, Iota allows that. This nuance may confuse those who decide to dig deeper into Iota after reading what you wrote about it.
Do you mean the computation of the PoW can be outsourced from the payer and the payer could pay a fee?
In that sense our designs are equivalent then. The assumption is that such outsourcing will be driven to very low profit margins near to costs. Also the payer is still in control of whom they outsource to, so control is still decentralized.