Mine is putting out about 470 fp with the .457 CF version. Mr. Hollowpoint doesn't have a review of the carbine, if I am not mistaken. Very few do, and none really with shot string numbers. However, the Carbine is the same gun as the SS, just without a moderator.
I like the carbine because it is light and maneuverable for blinds and stalking through the thick stuff. It has a lot of power (get the CF with TX2 valve) and it's simple.
I don't like it because the ergonomics are straight up junk, just like any of the Texans. Most uncomfortable gun I have ever shot. It badly needs a stock, and you have to use high to exta-high scope rings unless you want to cock your head sideways across the tank, and the cheap hollow grip feels like something off of a kids toy. You also have to make sure you are keeping every screw and surface oiled if you are planning on actually using it out in the woods. I bought it in August and started hunting hogs with it. Just my own sweat getting on it in the heat started some of the screws and pins rusting before I got home.
But it packs a heck of a wollop.