Me 3 ~ just without astrophotographing.
Feet on ground ? Mine is Mt. Pinos (~ 3800 m), CA.
Just don't go too high, I think those optics / mechanics may expand a little due to low air presure ? (may be not kidding)
Hi, my record is ~3,800m too without astrophotography.
Astrophotography experience is at 3,323m where I captured a scene and appeared in S&T magazine Sept. issue last year.
At such high place, with only 5mins exposure, the center of milky way become saturated.