It really depends on your knowlege of and confidence in the soundboard. As an event videographers, (weddings, etc.) I've learned not to trust DJ's and different church sound systems. Instead, I setup a Canon L2 (with shotgun mic) about six feet from a speaker, in an area where it won't be disturbed.
But if I was doing videography for, say a church, where I was familiar with the sound system and had confidence (faith?) that it would not get disconnected, etc., then I'd probably rather have the house sound, if they have good equipment.