I have the HD Vader but haven't taken it out of the box. From the looks of it the Jazzware helmet is an essential upgrade but the cape looks like it could use a switch as well. Does the animatronic seem like it would hold up with the weight of a wool cape on top?
I think the cape that comes with it looks pretty good, you just need to invest in a steamer to take out the wrinkles. As far as the helmet goes, I have no problems with the one it comes with as well but that is up to you.