Hi there,
trying to find out the differences between motherboard revisions is like looking for a needle in a haystack and when Gigabyte have been asked by other users their response has been less than forthcoming. Sometimes the changes are subtle, being things like different coloured RAM Slots or a design tweak to the layout. On other occasions the changes have been a little more radical but Gigabyte claim the the performance is not affected by them.
Personally I usually prefer the earlier revisions of motherboards as these are normally the ones that have been reviewed and tested. The thing to remember though is: Gigabyte's Warranty is from date of manufacture not from the day you buy it and, being one of the early versions of the board the warranty period will therefore be shorter.