The only "issue" that I ever had with my VP150 was when I had it sitting directly on top of my Mits 65" RPTV without the little rubber bumpers on the bottom. The sound seemed to transmit through the bottom of the 150, and into the TV. The sound coming through the screen was not good. It could be described as "hollow", I guess. I put a board across the top of the TV (it's sitting on some folded up rags at each edge of the TV to keep the weight off of the center of the TV), and put the VP150 with bumpers in place on top of the board. Problem solved.
Calibrated with Avia, MY vp150 is at -2dB, and the M60s are at +2dB. For some movies, I bump the 150 to -1dB.
The reason that the 150 has a higher wattage rating is that it's lower resistance allows more current to flow.
If you apply 10 volts to a 6 ohm load it will draw 1.6 amps. Since power = I(amps)*E(volts), it will consume 16 watts of power. (by converting electrical energy into sound waves)
Apply that same 10 volts to an 8 ohm load, and you get 1.25 amps. The power used would be 10v * 1.25a, or 12.5 watts.
This means that the VP150 will use 22% more power than an M60 when you send them both the exact same 10v signal.
