I wouldn't say "NEED". IMO, the EB Batman's stock cape is very good particularly the way it drapes that some people even use it on their QS001. The custom capes are OPTIONAL for the EB Batman. Now QS001, that's one that does need a better cape. I can't tell about QS009 since I don't have it. The EB mouthplates though? Well, they all are a home run to me @ EB's first try on Bale and his Batman.
Anyway, after watching all of Dean Knight's videos I thought that this figure is a must if you want a 1/4 scale representation of the Begins suit and don't have neither NECA's nor EB's version. If you have NECA's and want a higher-end version, then maybe get this. If you have EB's and are wondering if you should spend another half grand to replace it with the new (I'm calling it new instead of an upgrade), I'd say no need. Considering EB's price vs HTs while neither is perfect anyway, it's better to stick with what you have and save that cash.