HDRs generally look either fake or bad, though, since the whole point is to cram a great deal of tonal range into the relatively narrow range of a monitor or a paper. The easy way to to simply flatten things out, and that looks, well, flat. The hard way is to employ local contrast to create the illusion of a greater tonal range than exists, to retain the sensation of looking at a scene with a very very long tonal range.
In reality, these tricks will only take you so far, if the range is too great, you will wind up with flatness, the appearance of bizarre light, or just an indescribable weird look, because you simply cannot fool the eye that far. I don't know any rules of thumb, but I don't think you can really get much more than a couple of "visual" stops on top of what your medium will render by itself without one or more of the strange side effects turning up.
Of course, the HDR "look" is now a thing, people expect it and like it. They recognize it immediately when it's overdone, and post lots of comments on it, encouraging further bad behavior.