Put in a pair of locking trem studs, replace the pickups and do a bit of touch-up work on the frets, and the RGT42 is probably an outstanding guitar.
Even in its stock form, it's an excellent value. The ones i've seen i've been very impressed with. The quality of Korean guitars has improved by leaps and bounds in the last few years. The 1570 still has the Prestige neck, which probably has a little more TLC used in the fretting, but i think the RGT42 has the bones of a really excellent guitar, and just needs a little bit of final finesse.