Re: A little help. Question about S and SA series bridges.
I've got SA260FM. It is gorgeous guitar, especialy for the money. I like the singlecoil very much (my first guitar with SC, I used to play LP).
If you wan't FR, get guitar with FR. You will not able to do things like Satch or Steve on Willkinson type bridge (SAT30 is such a bridge). But if you wind your string carefully, have a good nut and saddles on SAT30 and setup, it will be pretty stable. And if you change tuning machines for locking type (Shaller or Sperzel, it will be even better). Have a look on nut, cause some SA models haven't propperly cut nut, it may cause tuning problems.
ZERO bridge is at least as good as Edge Pro if not better. It is more like Kahler bridge (on ball bearings, not knife edges like other FR bridges). It is very stable, you can play doublestops with bending, and it will not drasticaly change in pitch when you break a string (unlike FR bridges). I've heard it will not change in tune if you break one of the 3 top strings (g, b, e). You can set the stiffness of the trem and some of them have D tuner. But it is a bigger and heavier bridge than EP, some say more stiff (not spongy feeling) and I don't know if quality of the bridge is same on Korean and Prestige (Japanese) models.