Do heterosexual men ever have the experience of being extremely uncomfortable around women who are superficially be not that much different from other women that the men would find at least tolerable?

I can only think of one occasion. A female classmate who had had less than 5 minutes of conversation with me announced her cancer treatment and recent bad relationship, then made overtures about meeting outside of class. Basically, forcing intimacy waaaay too fast. This was followed by a lot of "oh look, we're coincidentally on the same bus" sort of events, despite my consciously unfriendly demeanor and monosyllabic conversation.