I used to have a JS100 that I upgraded to Seymour Duncan Pearly Gates
in the neck and TB6 in the bridge. I don't use the trem on it, and it is a wonderful guitar for that price. Very nice neck, very nice sound especially with the SD's and the coila-tap is great too.
Bottom line, the JS100 is a very nice guitar and especially if you don't use the trem (as I do), block it = more sustain, stability, and a wonderful axe wfor a decent price (especially if you get it used). Also, the transparent red finish is one of the nicest I have seen on a guitar.
I would swap the stock pickups for Dimarzio's or Seymours (see above) though, because the Ibanes INF pickups
DO really suck !
Bottomline : pickups changed and fixed trem (or just not using it) = JS100 worth hours and hours of great playing !