Thanks, @hvvelo! This is exactly what I’m trying to figure out–if there is any reason to go for direct drive given my situation. The only argument I’ve heard that is at all convincing is the possibility of not slipping when doing grinders. I bet with the clamping mechanism where I can tighten it down more, as @hugo1 suggests, I think I might be better off. The Clever Training/REI sales are the things that got me thinking about the Core, though, which is why I was considering it in the first place.
The whole “keep the chain clean” thing is possibly not going to happen on this bike… I ride it in the rain, and so it’s more likely to be messy. I pretty much just assume that this bike is going to need a drive train overhaul more often than the other one.
It sounds like I think I may go for the Snap, after all of this conversation, since I can’t seem to find a really good reason to go for the Core or any other direct-drive.