Every LT barrel in 5.56 I've seen was MOA or better with the right ammo and shooter, 5rd groups. Most factory guns, some builds.
I don't think I ever gauged a gas port, but the systems were balanced and the guns ran with chosen ammo.
3rd groups provide only a clue, but 5s are useful and 10s really do the talking.
I don't know if the barrel in the original link is from the Stealth line. The Stealth barrels are GTG.
For $699 complete sans optic it's certainly worth a try, and more worthy of benefit of the doubt than a bunch of others at that price point.