RG2770 is a Prestige RG made only for japanese market, so it is quite rare outside Japan (and it's discontinued as well as 8570). RG8570 is J Custom model (as well for japanese market, but only in limited production, and some work on it were done by hand - J Custom models were build to celebrate japanese craftsmanship, in small production numbers and available only in Japan, and somethimes in limited stock outside of Japan). But now, the new JC models are more common and thanks to Ishibashi available for customers outside Japan, so the new JC's are not as rare as the old ones.
IMHO they look same, but JC's have better quality woods, pickups, maybe higher grade maple tops, the workmanship is much better (especially the neck and work on frets), and it's got maple binding on body, neck and headstock. RG2770 has no binding (maybe body, but no neck and headstock).
IMHO they look same, but JC's have better quality woods, pickups, maybe higher grade maple tops, the workmanship is much better (especially the neck and work on frets), and it's got maple binding on body, neck and headstock. RG2770 has no binding (maybe body, but no neck and headstock).