Hi Joe,
As Ajax has correctly pointed out, pink noise is an extremely critical test signal (and useful). Please experiment with placement of your VP150. It is possible to find a location where you can get a seamless soundstage with the M80s (this advice also applies to the VP100). I've done exhaustive experiments with both models as well as using identical speakers across the front.
Placement issues and room/boundary effects are such that even if you use identical speakers across the front, the center will never sound exactly identical to the left and rights when you use pink noise.
But by trying different locations, you can get the timbral match with the VP150 and your M80s close enough that you will not notice timbral colorations with movie dialog or vocals (or instrumentals) when all three are running.
Regards,
