Conrad, welcome to Axiom. The VP160 has a T/M configuration that creates no off-axis problem, so it can be considered to be essentially identical in response to the M60.

As far as the question of tweeter level goes, this would be somewhat of an issue regardless of what center speaker(or mains)that you use, but generally this would have a minor effect on the second row if the height was optimal for the first row.

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Enjoy the music, not the equipment.