Do you happen to know what "overhead of events" actually constitutes, even if your knowledge is only related to a specific example?
Well the runtime is impossible to read now, but I know from past experience that it has a bit of an abstraction layer as everything has to be looked up sort of like a function. That's the nature of an engine not written from custom code.
The code is compiled, so the difference between the two really isn't that big a deal.
The main gain from code would be some optimisation that the engine doesn't offer.
Which means that since each game is different, trying to come up with a meaningful difference between the two is pointless, unless it's for the corner cases.
Or you really like to code.