Had the Pro Streets on my Softail and really liked the sound and performance. I had the turnout ones so I couldn't remove baffles or nothing but they sounded bad *** and looked killer but I would scrape the rear pipe on tight right handers.
I don't think you can find a better 2 into 1 than a fatcat. Fit, Finish and performance are second to none in my opinion. Not the loudest pipe but it has a good deep growl at a steady throttle and really barks when you twist your wrist.
The pro street's that I have heard were all silly loud and won't have the performance of a two into one setup, but assuming they were stock and not modified pipes that I heard and you want loud I guess that is the way to go.