hypothesis—that it is really hard to over-ride the immediate discomfort of an unpleasant decision—is to look at whether aversions of comparable or greater magnitude are hard to override. I think the answer in general is 'no.' Consider going swimming and having to overcome the pain of entering water colder than surrounding. This pain, less momentary than the one in question and (more or less) equally discounted, doesn't produce problematic hesitation.

I can't agree with you - it most definitely does produce a problematic hesitation. If you're bringing this example, then I'd say that it is evidence that the general answer is 'yes', at least for a certain subpopulation of homo sapiens.