Looking from a manufacturer's standpoint, it means even more parts commonality between the AR15 platform, and their tooling etc can be "unified" leading to cost savings. With common parts to both the AR15/M4 platform and the GII platform, the manufacturer does not need to make and stock as much of these different components since they can go into any gun.
The "current" AR10/LR308 pattern has a bolt carrier that is 1.25" diameter front end with a 1" (0.998") tail end. In the GII, the BCG has become like the AR15 bolt carrier with constant 1" diameter from the bolt end to the tail end. The 308 bolt, however is quite a bit larger, and from the pics in the press release & promo page, you can see that the bolt carrier wall is significantly thinner to accommodate the larger bolt. If you look closely, the bolt has also changed - where the current bolt has a separate "DI piston" tail, the new bolt has the piston integrated into the rear end.
Feedramps - great idea but I think it may be unnecessary. The ramps are more aggressive and cut into the barrel extension significantly more, therefore the remaining aluminum ramps in that spot would be thinner and weaker. The steel ramps are a probably a workaround for this, but I'm wondering what additional stresses are being added to the front pivot pin area, especially with lots of us opening and closing that area when we futz with our rifles all the time.
Execution wise, I believe they've done a good job by trying to evolve the original AR-10 based design, but how it holds up is still left to be seen..... only time will tell, I guess.