For me the biggest hurdle was scaling. I used the Pepakura software to help with this and I realized that I could have cut a few more corners as far as piecing it all together. I have a full Predator costume that is 95% latex with the rest being resin so it's a little heavy. This was a nice change with the foam. It'a also easier to put on and take off.
My next objective is to marry the two processes in making a full Protoss Zealot. I'll sculpt the head, hands and feet (maybe some other parts, not sure yet) and mold them with latex, then make the armor out of foam. It'll be a considerable bigger project altogether, but using foam to make the armor will speed things up considerably.