I have no experience with them. What did they rate their flow at for 28 in. vacuum? You can compare that number to the flow rates for the CATCO, Carsound, Random Tech, a testpipe, and stock cat in my cat article here to see if it's better that way.
Also remember that the construction, fitment, and longevity of a cat is also important. You don't want to be changing a cat because the bricks rattle in less than a year from regular driving or make trips to the hardware store during installation to "make it fit" without leaks because the fitment sucks.