First, and most obvious, you're never going to know how well that might work in your room until you try it in your room.

Lastly, I think that Randy's comments are appropos; part of the crossover design would deal with baffle-step correction, and would differ based on the size and configuration of the surface upon which the tweeter is mounted. i.e. ALL other things being equal, the crossover design is likely different based on the speaker's intended orientation.

bibere usque ad hilaritatem