In theory, the T-M-M (or M-M-T) layout in a center-channel design could sound better than the typical M-T-M horizontal array--but with severely compromised lateral off-axis dispersion to the left or right side, depending on which way you lay out the drivers.
All speaker design is a matter of trade-offs. Simply placing any speaker--regardless of its driver layout--on top of or below a TV monitor changes its timbral signature because of the large front surface that the TV screen presents to the center channel speaker. Even wall-mounting a center-channel behind the TV monitor will significantly alter its timbral quality.
So in our search for absolute fidelity and a perfect timbral match do we simply do without a center speaker? That will certainly eliminate any timbral mismatch, that's for sure! But now we have to sit dead-center on the couch or the dialogue collapses to the left or right speaker. And no one else can participate, because the dialogue will follow them to the nearest speaker. Bummer! Even worse, it's sometimes hard to discern the dialogue and now we can't separately control its level.
So we accept a reasonable compromise between timbral fidelity, dialogue intelligibility, and social convenience in viewing home theater. The VP150 seems to get most everything right--a good timbral match between the M22ti's with excellent lateral dispersion to either side. The VP100 offers an agreeable combination of reasonable timbral match, good off-axis lateral dispersion to either side, price, and intelligibility. I can't tell you not to try an M22ti in the center--but will you accept the uneven lateral dispersion characteristics? Did the reviewer even address some of the inherent difficulties and trade-offs of center-channel speaker design?
Axiom Resident Expert