I have Boig on 1 car, and Gasn on the 2nd car. In my opinion, what really matters most in that decision is how you want them finished. I had my Boig pipes cera-coated black because they don't offer them in any finish. (obviously you can choose a lot of options on how to have them coated)

I picked the gasn's for car 2 because I was after the polished look, and they are gorgeous.

Both bolted right up and work well. Both sound great.

Rian