I dont regard the relocated pin as a deal breaker, but it is annoying.
It's hard to argue that forcing the consumer to buy a whole rifle is not better for HK.
Forcing the consumer to marry your brand and limit consumer mobility translates to a steady stream of cash after the initial purchase. It wouldnt be good for the SCAR/XCR/556 parent companies if they were disposable in the way Bushmaster is (You can buy a Bushmaster carbine, and never have a need to give them addtional business because you can easily be serviced by hundreds of vendors selling the same/similar product).
More important to me is how compatible the MR556 is with the 416. Can I gut a 416 upper for the barrel, spare parts etc etc, and drop them into MR556. If I can build a 416 "clone" with all HK parts, I can live with the upper/AR15 lower issue