Dark vs. Altitude revised!

I think that my question was misunderstood so I am restating it.
If you have the choice between dark skies and a lower elevation and light polution (Sky Glow) at a higher elevation, which do you think would be the better site?
I am not asking if you can have a high elevation with darks skies. I am asking which scenario would be the most prefered.
Floyd

Dark sky.

I've found that it isn't so much the density of the air but the turbulence that affects seeing. I live in CO at about 5,600 ft. Upper level turbulance is a big problem here which more than offsets the effects of less pressure.

The less density the better, but that effect is much less than the effect of good dark skies.

Actually some of the best visual nights I've had were partly cloudy. Often those cloudless nights are the result of atmospheric turbulance that has sheered away all the clouds.