I compared my VP150 with an M2 for center channel duties. There was a noticeable improvement (to me, in my room) with a vertical center channel over the VP150. You might want to give an M2 or M22 a try for center duties if you have the space. Keep in mind I have the in on wall versions, and the improvement was enough for me to go through the effort to cut, patch and paint my drywall for the speaker switch.
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Dan
In/On Wall 500 w M2 Center Channel