There's a long thread somewhere about the general uselessness of mobile check in. Supposedly, it let's the hotel organize check ins a little better, which theoretically should help with upgrades. It's a small thing though.

As far as the hotel briefing you on amenities at check in, that's really property specific, not a Marriott thing. My only real beef with this is when the concierge lounge is somewhere I don't expect. In a Missouri property recently, the lounge was accessed by walking through part of the lobby restaurant, with no signs and poorly marked at the entrance. I had to ask at the front desk. At least tell me what floor it's on when I check in. Some properties do and some don't.