I've been using a pair of Biz (bizzes? bizzum?) and right now they're my favorite for OH. I like them better as OH's then the MP1-C's or L3's, which I also have pairs of.
I guess I'm using them differently then other folks. Saucyjack and Nathan have called them clean, though I like them cuz they have a thickness in the midrange that I really dig. That's the first word I would use in describing them - thick.
Maybe I don't really know how they work and I'm driving the crap out of them! Usually I set them up so really hard drum hits just barely put the input meters in the yellow, then adjust the output so my audiofire meters are hitting -3 on really hard hits. Maybe that's a bit high, but I like the sound I'm getting. I haven't been using them much in dual mode.
Anyway, I find the MP1-A's to be the clean 500 preamps of the ones I have.
Haven't used the SH gear.
Dunno if it's helpful or not, but here's a couple of clips - biz1 biz2
Both are m/s setups though a pair of biz then through a pair of 560's. The 560's have a little low cut happening on the bottom 2 bands, plus a little tiny maybe 1db bump around 1 or 2k. Can't remember which.
They both have a Sony C-48 for the side, the first has a AT4060 for the mid, the 2nd a AT4051.
No plugs except the phase reverse for the m/s setup.
Home studio, cheap kit, shitty engineer.