I put Viking 3 to 1 on mine, Super hot to start off. But after working with the fella's on this site got a good tune that has helped a lot. I'm slowly tweaking the air/fuel settings trying to get rid of some decel popping. Overall pretty happy with the set-up.
Paul is good to work with and takes pride in is work that shows in his product.
I’m doing a suspension upgrade now and talking with Neville Lush about cams and pistons. The pipes are on the small side but overall I expect the bike to become a nice torque producer from the bottom up. Sure I give up a few high rpm ponies but most of my riding is done in the mountains and torque is king on these tight roads.