Spending an extra $3 to $4 grand doesn't seem like a good option to me, plus at the time only 10.4 inch barrel was readily available, with MR223 you get a match grade barrel with an H&K lower. The only difference is the pins being off set by 6mm.
Its a great rifle, who needs the MR556 it isn't even completely made in Germany, other company's are getting a piece of the action making it too. This is fine, but up here in Canada we are actually getting a better deal, plus remember we have ours selling up here already where in the US they are still waiting, mind you they have better access to the actual 416 uppers.
The differences here are just the markings on the rifle, pins offset, and no full-auto. Consider us lucky we still have this as an option.