As far as I am aware the backspacing is all the same..
But without re-creating the wheel(hehe), there is of course the 03' style, which are a machined finish. Then there is the above 04-05' style, then there is the Rubihara wheel, which is simply a painted 03-05 style. Lastly there are the 06's which have a dish in between the spokes.
Best way to show this is to give you a link to something right here on GL: You can see a side by side.