Ohms question for speaker experts????

[JimShaw]

My in-ceiling speakers can be switched to run either 4, 6 or 8 Ohms. I have been told by the manufacture if my receiver is able, I should be using 4 Ohms.

The manufacturer of my receiver has told me my receiver is THX certified which means it can run 4 Ohms with no problems.

I know 4 Ohms pulls more watts from the receiver and 8 Ohms uses the receiver less.

I know if I use 4 Ohms I do not need to turn the volume up on the receiver as much as I would the 8 Ohms to reach the same sound level.

The above is my knowledge of Ohms.

Why would I used 4 Ohms over 6 or 8??? If the only difference between them is turning the volume up on my receiver to reach the same sound.

Or is there another reason that I am not aware??