I'm fairly new to CofC, and I recently finished running the introductory campaign out of the back of Cthulhu Invictus. I'm not sure what I thought of it; it didn't provide too much advice in terms of what to do when the players jump the rails of the fairly linear plot. However, in terms of the players, I was very happy with how it worked out. For a group of players whose primary experience was with Dungeons and Dragons beforehand, they were pretty good at changing gears to be a bit less hack-and-slashy. I was also happy with how well they adapted to the more deadly aspects of the system.
Moving forward, I'm planning on running a few 20's scenarios, and then starting into a larger campaign next semester. I'm lucky enough to go to a university with a library with a copy of Horror on the Orient Express, and the players really want to give it a try, especially before one of them graduates. On the up side, it gives me an excuse to listen to the Innsmouth House recording of the game, which I'd been putting off in hopes of playing it. I have resigned myself to the fact that I won't be able to play it any time soon, so at least I'll be able to run it for a group instead.