Rode it twice on Monday. (both on Digger) It was running two trains.
First ride in Row 9: MCBR did not engage at all.
Second Ride Row 4: MCBR engaged quite noticeably.
Things you should know: I'm an Intamin fanboy. Never ridden an RMC before. Millennium Force, Maverick, TTD are life.
My overall impression is that it is a great, enjoyable ride. My first RMC. I can see why these coasters are so popular. I will however stop short of saying its my favorite. Mainly because it didn't do what I thought it would do. My ONLY complaint is that it is strangely "too refined." I wanted it to kick my butt a little more than it did. My favorite parts were the two lateral "surprises" (the first, right before the MCBR: the second, right after the 4th inversion.) I LOVED that. I wish it had more of that.
The first "top hat" has eye popping airtime. I'd never felt it quite like that before.
The engineering is incredible. I don't know how they made it so smooth. The final airtime bunny hops are so... "springy"... you just bounce, its crazy! I didn't know a coaster could to that! I thought they would be really violent and they weren't... and that kinda actually disappointed me a little.
I loved the ride. It was fun, comfortable, and I think, very rider friendly. RMC can definitely go higher and faster, and still likely provide a better experience than the other manufacturers out there.