When the rubber hits the road and all things are considered I suggest you find a quality pipe with good fit, chrome, heatshields, and sound that appeals to your ears. The swoopy bling bling pipes will HP fine but have large torque dips in the areas where we ride most, so there are givebacks. In the end on a stock motor there will not be that much difference from any of the pipes mentioned here if WOT hp is the only criteria.
Regarding the short list
V&H makes a quality product with excellent customer support. The performance winner is the propipe. Most are loud but not unruly with baffles. The others from V&H get good points for bling especially the radius pipes but the edge in overall performance goes to the Propipe. The propipe will also support higher hp levels where the short list of "what works and what doesn't" becomes more critical.
The D&D FatCat with the performance baffle is ear shattering but works well. I think I would be inclined to use the standard baffle on a stocker, better torque and little to no WOT hp loss. Much happier ears, trust me this all comes from first hand experience. Rumor is D&D will release a quieter baffle soon