What I'm wondering though is what constitutes "runway in sight"? I mean, in some cases that's going to be obvious (ie., you can see the runway clear as day long before minimums.) But what if the cloud base is right at minimum and you can kind of see outside, but not in every direction (ie. maybe it's slightly clearer just a bit to your left than to your right.)
What do you have to see to consider the runway in sight? The whole runway? Just the lights? Just the approach lights? Just the VASI/PAPI? Would it be considered enough if, perhaps, you could see a windsock that you know is close to the runway? Or perhaps there's a cross street right before the runway that you're very familiar with, would that work? What would be considered "runway in sight" so that you can continue the approach rather than going missed?
Note/Clarification: The general rule, of course, is "when in doubt, go missed". So in a lot of ways this question is academic. What I would love, though, is a two part answer, with one part that has the exact rules (per the FAA) and the other with some common sense guidance on when to continue and when to go missed.