je may have the best "off the shelf" pistons, im not going into that. however, if you ask any PROFESSIONAL racer, not just the guy next door with a drag car, they will tell you that they have custom pistons. endyn mass produces custom pistons, this is a complete contradiction of terms but hear me out. they make the design for the application, send it to wiseco(just as good as je plus more 4 valve experience), then get the final product and custom shape it by hand. they only work with hondas and so in a way, it is a custom piston. there is much more r&d into an endyn piston than a je. for another motor je may be the best, but not for your honda.
oe pistons are designed to work with a honda head and they are a great value but many compromises are made in a stock piston. if you are designing a motor similar to the jdm itr motor then you should use those pistons but if you want the most you can possibly get out of your 1.8 then you may want to look into spending the extra cash.
the endyns are much more forgiving than the stock honda slugs and unless you are having honda tune your car then youll need the extra forgiveness.