I bought my first one from them because it was a cheap way to get a threaded barrel to test some ideas. I was happy enough with the performance to buy a 2nd, non-threaded barrel. I shot both barrels side-by-side with a factory Glock barrel in the P80 and my G19-3 and couldn't tell a difference between the Glock barrel and the CombatArmory ones.
Also, they are good guys who provide good customer service. On the 2nd order, they sent me another threaded barrel instead of the unthreaded one I ordered. I contacted them, fully intending to send the incorrect barrel back, but they sent me the correct one and told me to keep the incorrect one. Not needing two threaded barrels, I gave that one away here at PF.
Chris