I don't know that so many of us are so well-trained as just politely housebroken. But Ozpeter, Mr Zemlin and SteveG do a good bit of location recording and will all agree that if you don't have a handle on how the room will respond, a figure-8 pickup is an ace-in-the-hole because of the options it gives you after-the-fact.
Hmm... the more open mics you put into any given acoustic, the less good applause will sound - which is why most broadcasters mic applause separately! I'm fortunate - I don't do so much recording with an audience present these days, so I don't have the option to listen to it live very often, but I have to say that I've never really regarded it as any sort of arbiter of how good the wanted sound is going to be. But MC's correct in one sense - if you want to capture as much of the acoustic in a space as you reasonably can, a fig-8 is a good bet for stereo. And that's quite often what I would use as a distant pair - a lot of flexibilty there.
As far as the timbre/acoustic nature of recorded applause being an indicator of success while on an unfamiliar location, in my opinion it's a valid piece of the puzzle, but only one of a number of them.
I think that as far as it goes, I'd agree with that. But since I do what the broadcasters do on those few occasions that I do live stuff, I don't usually think about it from that POV, and I don't think that I'd like to rely on it...
If I can get a sound that's acceptably similar in the control space on near-field monitors to what I can hear in the space itself, I'm generally satisfied. Okay, it's become a lot easier to achieve this since I got the alter-it-after-the-event Soundfield, but the basic principles of how to achieve this haven't changed, and in a very real way, the SF makes it easier, because it's easy to listen to it as a mono omni mic - always a good starting point.
But it's been interesting over the last couple of years - I've thrown out some of the practices I previously used as far as micing is concerned, and I'm trying some new stuff - which I'm still analysing. The latest one (although not used in anger yet) is a Jecklin Disk, although I have to say that it was really invented by Blumlein in the 1930's, and not Jecklin at all. I may be unpopular in some quarters for saying that, but UK Patent 394,325 fig. 1 has it there, for all to see. And Blumlein's ideas seem to have quite a knack of working out, one way or another.
But I reckon that a pair of omnis either side of a disk would probably make a good applause recording, certainly!