After researching the niner carbines, I decided on a factory Colt 6450 that I found for $1100 brand new. So far, it has been perfect with the supplied 32 round Colt mags and it's a hoot to shoot. One oddity is that it has the large trigger group pins.....I didn't notice that until I tried to stick a Wilson in it. I haven't really wrung it out for accuracy but informally it surely seems very good, and it's really light with it's skinny 16" barrel. On the down side to some may be the old style carry handle upper, but I like it for what it is.
I haven't *really* figured out what it's for yet other than a range toy, but I do like it. I may run it in a 3-gun match one time if they will let me.
Dan