Right. At normal volumes the VP150 will draw proportionally more power from the amplifier than an 8 ohm would at the same volume setting. Whether that results in playing more loudly or not is totally a function of the sensitivity of the speaker, but it does *have* a bit more power to play with.
WHen you turn the volume up to clipping, you may or may not get more power into a 6 ohm speaker than an 8 ohm speaker, depending on whether your amplifier runs out of voltage or current first at 8 ohms. If it runs out of voltage first then you can get more power into a 6 ohm speaker -- if it runs out of current first then you won't.
Normally it's a bit more complicated, ie the amp runs out of voltage first with an 8 ohm speaker, runs out of current first with a 4 ohm speaker, and could be either with a 6 ohm.
It sounds nice, that's what matters
