None of those really. If it's someone I haven't met before, as I draw alongside I say with a smile, "Don't worry, it's electric".
There's usually a friendly response like "Wish this was" or "I don't blame you".
Half an hour ago coming out of the supermarket, a lady parking her bike looked at my Q bike and asked where I'd come from, when I told her she responded, "I don't blame you with those hills".
Increasingly I find the reaction to my e-bikes is friendly in my area, perhaps because it's hilly, and the only shout of "cheating" I've heard in the last year or so was from a couple of local kids waiting at a bus stop! Apparently riding in a bus isn't cheating.

.