I think three shot groups are pretty typical for rifles. I usually only see 5 shot groups on handguns. Cloverleaf groups at 100yds and <2" groups at 200yds are damn fine groups and damn fine shooting. I'd say the gun, the round, and the shooter are all doing their jobs!!
This confirms that at least in the accuracy column, the 450 Bushmaster should be a good deer, bear, hog gun out to 200yds. So far, this is definitely going on my Christmas list. I would get the barrel and upper, and swap it on and off my existing V-Match. I won't be shooting them both at the same time, so I might as well save the extra $500 for a full gun.
The next data that will be nice to hear is how the bullet performs on real game in the field. I sure hope you will let us know how it works when you have a chance to take some game at various distances!!