IMO the improvement was across the board. I probably noticed it more for most music as I usually listen to it more critically.
The biggest improvement I noticed was better dynamic and timbre matching of the front 3 speakers. There just seemed to be a hole in the midbass with the VP150 which the M80 filled in. This made bass instruments and male voices sound noticeably more natural for both movies and music. This also created a more robust “wall-of-sound” seeming more “movie-like” and more realistic sounding for concert CD/DVDs.
One caveat is the difference in presentation between a horizontal and vertical speaker. The vertical M80 IMO makes well recorded music sound more precise with better placement of instruments and vocalists. However, if sitting close it can cause somewhat of a breakdown of the front soundstage where the center can be heard as distinct from the mains when watching movies. OTOH, a horizontal center blends across the front soundstage for movies more easily. However, it gives less precise audio queues for music since the drivers are spread out a couple to several feet. It can make a vocalist sound like their mouth is a couple feet wide if sitting to close. Note that the farther you sit and the closer together the speakers are minimizes all these effects causing both horizontal and vertical centers to sound more similar IMO.
I am actually toying with the idea of getting a VP180 myself. I would either mount it above my screen and run it in tandem with my current M80 center for movies and switch it off using only the regular M80 for well recorded multi-channel music. The other option I’m considering is making a swiveling speaker stand at work. So I can use just one VP180 under the screen where my M80 is and spin it between horizontal and vertical for movies and some music respectively.
