Hmmm, very well put. Y'know, I guess in my experience, I've had very few good ones with "epic" level stuff, so I suppose that is why I have the POV I do. I do find it rare, however, that a DM has run a decent game on large levels. In one specific instance, I knew for a fact that the DM just wanted to be able to use big massive monsters, just to check out their crazy abilities! Now, that is all fine and good, but with no proper story (imho) to tie it together, even a half decent premise to warrant such encounters, made it boring imho. But yes, if the DM uses their brain, any level of adventure can be satisfying, as you eloquently state.