Factory Pro +4 Ignition Advance
Can't speak for gains yet, haven't ridden the bike since this mod was done.
Installation was pretty easy. Just pop off the side cover, remove bolt, swap parts...then reverse the steps till the bike looks like it did when you started (43ft/lbs for that bolt). One trick in doing this to save yourself an oil change is put the bike tires on some wood, a book, your little sister....anything that will support it's weight and raise the bike up an inch or so. Then let the bike lean on the kick stand. The oil will pool to the other side of the engine enough to allow you to remove the engine cover with no oil loss.