I've never played on Cake, but I've played in some weak tight FR games. This is pretty strong. Blind battle and no info on opponent are really the only things that lead towards a call. Much more so than the strength of your hand in a vacuum. I don't think I want to be stacking off here though. I can't fault you for folding. I can't fault you for calling and seeing if he has it in him to fire river again either.

However, if I end up folding and later find out that he's a lunatic, I'm probably putting my head through a wall.

One thing that I'm really trying to jam into my brain lately is that most lower stakes players generally don't check raise, or even raise, the turn without a big hand. I'm trying to remember it when it happens to me and I'm also trying to use that knowledge myself to semi-bluff against some better players in the right spots.