I love the SP B1 mic. I use it as a room mic in font of the kit, it works great and I've used it on mounted toms and it worked great. I didn't like it at all on kick. I kind of got "the sound of slamming a metal door in a large empty warehouse" sound. Padding the signal at the board, using a roll off, eq'ing it up the wazoo all improved the sound,but why? There are so many relatively inexpensive mics that are made specifically for kick drum that work.
The B1 is just SO good on so many other things, why use it for something it isn't that good on?