Those are really good questions
k1lroy. Let me answer the 2nd one first.
Its not the method. Its the time and effort one puts in. I've seen foam builds that look just as good as a printed one and pepakura is just another method. One is not any better that the other since again it how much time you put into each piece will determine the quality of the end result. Its also what you feel most comfortable with using. People with limited space find that doing the pepakura method is not possible due to the harmful vapors the resin gives off. And printing out an entire suit can be expensive. And some people find foam too forgiving and has a short life span.
Now as to your 1st question, there are many pros and cons for each of these methods. And everyone has a different take on each of them. But those are like dime a dozen. it is you and your opinion that is going to matter in the end. I started with foam.....correction, foamboard......then I switched to EVA foam. Now I'm trying my hand in 3D printing and a full Pep build...... Ill let you know after I've finished.