turner,
I had 3 kick mics to demo on my double headed birch 22x18 DW/Pacific kick.....the shure beta 52 ($189.00), the AKG D112 ($199.00) and
the Audix D6 ($199.00).
the beta 52 took me a lot of time to find its "sweet spot" inside my kick. (I had the most positioning problems with this mic) best position was upper left angleing towards the edge (above bottom of floor tom through the beater head).... overall the mic had a "honky" type mid range tone which I never could get used to. its "click" sound up close was more "flabby" sounding and "boomy"
the D112 sounded pretty cool. (though its sweet spot was dead center 3 inches off beater, slightly off center) I got a great click sound with a tougher bottom end and not as much mid range and its freq sat lower in the overall mix than the Beta 52.
The Audix D6 was the winner and the one I purchased. when I threw it in the kick, it sounded great at every position (no fussing) I really like the scooped mids as it enhanced the sub freguencies the most. the "click" was present but not as bright as the D112... the Audix was the "toughest" out of the three...now I'm not really into that Metalica slap sound and though I thought the D6 was heading in that direction at first, in the overall mix it sat the lowest, perfectly enhancing the bass guitars attack.
the way I classify these mics is the following:
the beta 56 feels like it hits you in the chest area.
the D112 hits you around the stomach
The D6 smacks you right in the balls!
its really worth getting a dedicated kick mic, especially for under $200.00 ... I use my B-1 as a mono room mic or when I'm recording brushes on my snare I get a bigger brush impact over the 57
of course everyones rooms, tuning, and tastes are different, this is just what I've found worked for me. I'm very pleased.
good luck.