The difference made by these pipes will be so very, VERY small that it will always end with whoever is the better rider. Plus, nobody has done a true comparison test with dyno results yet, and odds are nobody will anytime soon.
I think your best bet is to go with whichever one you like the best, which includes price, sound, looks, etc.
I've heard stories of the HMF pipes blowing cores on other quads (not Predators) and don't really want to even try one. I do recall from the dyno/comparison tests on other quads that the CT and White Brothers pipes are always at the top for peak horsepower, so I'm happy with my WB pipe.
If I were to get a full system, I would probably get the Trinty, but I don't see the point in spending $500 on a system when it won't do any good over the WB pipe. Trinity is known for doctoring their dyno numbers so I don't believe for a second what they publish on their site.
Rob