Guess I was up too late for math last night :-)
My free space before was 59.08, after was 72.44. What I did last night was (after-before) * conversion, when what I should have done was (after * conversion) - before. Conversion = 3.7 / 4
(72.44 * 3.7 / 4) - 59.08 = 7.93
That's more in line with what everybody else is reporting. Still, a nice chunk of extra space.