In my experience, you want a narrower radiation pattern in a small room than you do in a large room, and in most cases you want to use more toe-in than normal. This is to keep the energy in the early reflections to a minimum. To the extent that the MTM format reduces early reflections in the vertical plane imho it's theoretically a step in the right direction, but that narrowed vertical pattern of the midwoofers should carry over to the tweeter as well, which is seldom the case.