For a first time cosplayer, you're cosplay is pretty much spot on. As for what others have to say, you shouldn't really listen to them, unless they're giving you productive criticism or something along those lines. Compliments are even better. The fact you're going to wire in some working LED's for the sleeves, will make you stand out from most Len cosplayers, so there's a plus. Just keep up the good work. Not everyone on the internet is going to say nice things, but these kind of things happen. Good luck on your Len cosplay!