Well, first off, having several Goon guns myself, I can say that Goonerizing a gun is never a bad idea. Don't expect to have others be willing to reimburse you for your efforts should you decide to sell down the line, but anyway...
It's kind of up to you. You state you aren't interested in competition; well neither am I. But for my own satisfaction, I can honestly say stock factory guns pale in comparison once you've shot one of Goon's masterpieces even though the new ones are really, really good. Being as yours is a Pietta, you most likely won't have any short arbor issues. But the improvement in lockup and timing, trigger pull and hammer pull alone are worth the money spent IMHO. Plus, he does a beautiful job fire-bluing the screws, should they need it.
Will a stock out of box gun do you fine? Yes. Absolutely. Will you notice a difference with a Goon gun? You'd better believe it!