I think it depends on A) how good the band sounds live together and B) what kind of sound you're trying to achieve.
If the band or room sounds bad to begin with, i.e. some instruments louder than others, vocals not loud enough, etc... I usually use more mics. Also, if I want a tighter sound than a few mics I will use more. I like 2-3 mics out front that get the sound of the band live. If I need them, I will add mics to whatever instrument needs it. Vocals at the places I used to record were never loud enough, so I generally will take those from the house board. I've gotten really good results with very few mics and a lead from the board for vocals.
I also really like micing up each instrument, or at least most of them. Working with a three piece with one vocalist is simple with only 8 tracks, but the more you have the harder it will be if you can sum your channels. This usually sounds cleaner, but without a crowd mic it isn't very fun to listen to, in my opninion.
Two different ways to do the same thing. But like I said, they sound different and have varying levels of difficulty.
Rory
