Re: Prestige = Standard + TLC
If you're talking about the current prestige models compared to the older MIJ models, yes they are the same just with some more TLC on the prestige necks. If you're comparing the Prestiges with the MIK and MII/MIC(Indonesia/China) models, not really.
While it is possible to make an RG350 play just as well as a Prestige, there would be a good amount of hardware swapping. However, if you don't care about the trem, changing pickups, stripping the neck and getting some good fret leveling done can help a lot. Mind you, that's more $$$ that could have gone towards a better guitar to begin with.
(btw, the necks on an RG350 and a RG1570 are very different. While it is possible to get a luthier to shave down the neck on an RG350 to match the profile on the RG1570, it's quite expensive).