Lots of corps are using mics to bump up their brass sound. Crown uses it a lot, but there are others like SCV who use it for the small ensembles on the field, and to bump the impacts up, or phantom who has them all along the sideline to up the sound of their much smaller hornlike.
Musically, this is an incredibly well designed package, and having seen them rehearse it on the field, visually, its awesome as well. As it cleans, its going to surprise people.