That is about where I have mine set - and I have had them for about 4 years I think?
Unfortunately, I don't remember the model #'s
At first I drove around on them all set to 9 ... wow was THAT fun!
I enjoyed 'feeling the paint stripes' on the highway .. but I knew my passengers wouldnt, so i turned them back down a little bit
I do remember reading on other general 4x4 forums that the remote units were prone to be flaky. So that was never a consideration of mine. So just tune them in, and leave them there
Just remember to have them installed so you can easily reach the knob!