Olly is right (as he should be, people give him stuff to review so he must know what he is on about!) - the Race barrel kit is a Sanchez Machine SM-1. The barrel is a two-piece - one 14" main barrel with an insert that screws into the first 6" of the barrel and has cocker threads on the end. Because of this design, the insert always aligns perfectly with the front (and with the breach) and there's no funny little crevices to trap paint like the Freak has.
As for how good they are... well, I'm seriously thinking of rethreading all my non-cocker threaded guns to fit that barrel set. If you can get your hands on one, don't think twice about it (but I doubt any of us will be selling up any time soon!)