NS-10s are history, as Yamaha is no longer making them. Therefore not very relevant to the question, "Which monitors should I buy?" I will not argue that they are an "Industry Standard". Engineers seem to have a love/hate relationship with them. They can be found in use at all levels, from HomeRec on up to top $. Should EnVISION buy them? NO! Just because they are an "Industry Standard" does not make them the right choice. The only reasons I could see for wanting to try and find some NS10s used would be if 1) your ears are trained to them or 2) you expect to have others using your equipment that are used to them. Big studios will continue to have them around (until the replacement parts supplies dry up), 'cause everyone knows them, they are a "common ground" point of reference.
Queue's 2¢