I replaced mine with Dimarzio (big improvement over the stock ones). Only thing is they are larger than standard Ibanez ones so if you have a pickguard
equipped guitar you will have to bore out the hole by a couple of milimeters. I heard that CTS pots are the same size as Ibanez ones, so if you don't want to enlarge any holes (obviously not a good thing with pots mounted directly to the body / no pickguard) then go for those. CTS quality is apparently very good, but I haven't tried them.