Re: second hand sz320 or sz520
I believe the differences in the SZ320, the SZ520 and the SZR720 are mostly visual. Not really sure about the electronics, but I am pretty sure that they are all Ibanez pups of some sort. From what I remember though the 320 had no binding, dot fret markers- the 520 had body binding(maybe neck binding?, can't really remember) and had only 1 fret mrker, that being a flame on the 12th fret- the 720 had full body, neck and headstock binding and the earlier ones had flame fret markers at the normal positions(3rd, 5th, 7th, 9th, 12th, etc.). The later 720's had a multiple vine inlay if I'm not mistaken. All of the SZ's(320, 520 and 720) were all set neck, fixed TOM style bridges and were string through body.