"Full reversion to PNP" is misleading. What does "full" mean? Just SRD + ECS ... but without the polymorph school and real summons, right (because we don't have those)?
Full reversion but maybe with the kinds of rules and such from the Complete books (Deepwood Sniper, Acrobat, etc. are flavor from those). Great, that nets us Divine Metamagic - and I'd love to persist Divine Power on my cleric just like in PNP.
It's truly not as simple as those four words suggest.