Well, after 40 voters here is how the numbers work out. (1 voter had to be removed because he only voted once...

sigh...):
11 out of 40 voters (27.5%) voted 1, 10, 20; indicating they see no difference between fighter and wizard at those levels.
Including them, the others cause the averages to be decreased roughly 75% of the fighter level equals the wizard level, so 0.8, 7.56, and 14.68 would be the wizard levels equal to fighter levels 1, 10, and 20, respectively.
Without the 11 of 40, and just counting those who feel there is a difference, the averages are closer to about 67% +/- 5% of the fighter level equals the wizard level, so 0.724, 6.656, and 12.655, with the % decreasing at higher levels.
FWIW, there was one outlier on the low side, voting 0,1,3; but even compensating for that the numbers round to 1, 7, and 13 still.
We'll see how many more people vote and I'll update the numbers if we get a significant number of more voters.