It's interesting that we can train ourselves to ignore physical feedback. I don't know if it's a lack of practice or what, but I actually get more dizzy when spotting than when I turn without doing it.
I had to take a side trip to the link in the beginning of the article. It was of Michael Jackson spinning, and I had forgotten how impressive he was at it.
I do spotting so I don't wander all over the place when I spin. I still get little dizzy but recover quickly. I am quite good at spinning as I actually like the feeling of being dizzy, its a natural high for me and I never get nauseated.
Personally I like the look of the unfocused gaze in (most) belly dance. Spotting gives it a ballet asthetic for me. (The only time I saw spotting look good was in a Kazafy choreo with a series of hip drops followed by a pirouette - I guess because it looked like belly-ballet fusion)
Some years back we had a spin off with a ballet dancer of over 10 years experience spotting and another dancer using the unfocused gaze method. The latter won.