Well, I've now abandoned all hope that Poweramp will ever handle Ratings in a way that's even remotely useful... but it's still very disappointing, seeing how passionate the PA community is (was) about this feature and how it's been consistently ignored and blown off. And I guess that speaks volumes of the developer. The app advances to a certain point, it's seen as "good enough", then it's no longer supported (or the updates are painfully minor) and users are forced to shift to another option.
iSyncr + PlayerPro is a combo that's far from perfect, but at least it's able to accomplish what Poweramp has been promising for five years.