Agree with TDI. VP160/180's were not available at the time I tried the M2 switch from the VP150. However it's a moot point for me as I am limited to an on-wall setup. I am now very happy with my 3 M5 on walls across the front. It may look unconventional but I am very happy so far.
I think it would be interesting to try a comparison between say 3xM5 vs M5/VP160/M5. From all reports however, a VP160 would be a good improvement over a VP150 (though I've not had the pleasure to audition one myself).
In the end experiment and find what makes you happiest!
Cheers,
