don't really think a profiled or calibrated monitor is a big factor as long as the monitor is not overly bright or overly dark such that the brighter shades and darker ones are compressed...
Btw, to be really accurate, you should do the test in a dark room... I mean turn off your lights at nite.
I haven't tried the test yet cos sun is out and i got no time now...
Will try it tonite... seems fun...