I just tried out my new Bova Balls on acoustic guitar and must say I’m very impressed. They are “kinda” Omni and although I use omni on acoustic guitar quite a bit these things have a magic attached to them. They claim that the ball shaped housing (like the DPA) captures the higher frequencies in a more directional way than the bass frequencies. I was skeptical but now realize that those mics do unique things on a psychoacoustic level.
We tried X/Y, ORTF, near coincident and a few other random placements and ALL of them had the bass frequencies tightly up the middle, the low mids almost scooped and spread in a cool way and the highs dancing around the edges like magic dust. These mics are bright but not harsh, natural but also supernatural and they will be staying with me for a host of uses I’m sure.