I've used PTP in a number of non Yonex frames (Prince Phantom's, Angell's, Head Prestige) and it's a nice, soft poly with decent spin potential, at the price of an absolutely rubbish tension maintenance.
If you were to stick with Yonex strings, Polytour Fire, which is also round, is better in that respect, although not great by any measure. It's also slicker, so will have more snap back.
But really, Hyper G Round should be the one to try. It's a bit firmer than PTP at a similar gauge, but that's easy fix by dropping a couple of lbs on your usual tension. And with a price that's 40% less than either PTP or PTF, it's very hard to find any reason to stick with the Yonex strings, if you're paying for them.