Re: RG1550 and RGT42
With those mods, I'd say the RGT is actually the better option. Certain things about the 1550 will have been better from the factory, but assuming both guitars have had fretwork done since he's owned them, the neck profiles will be very similar and there'll be no difference between the fretwork.
As for korean guitars, I've had no problems with korean stuff, the RGTs are pretty good in fact. The only things I'd change in terms of longevity, have already been replaced by the owner. I'd enjoy one with stainless steel frets, but ibanez don't make anything with SS frets, so its an academic difference.