Personally, if he has the room for an M22 as a center I would do it. I find the M22 to handle male voices slightly better than either the VP100 or VP150. A vertical center also has better dispersion charcteristics than a horizontal center which does, IMO, yield better sound quality for all seating points.
So far as what you can read at other sites about lobing etc, I know Ian/Alan have both mentioned it is a quality that can be measured but very rarely affects Sound Quality and I have to agree. I have had no issues with either the VP100 nor the VP150.
Both of Axioms centers play very loud, just the 150 is capable of more SPL due to extra drivers.
