those are factory plugs ,1st change, the new ones are the same size but the irridium version.not sure if there hotter.Looks like you are running a little rich or cold by the looks of your plugs.
I did notice a difference with this oil (smoother).Thats good engine oil there . Smells like dilluted rocket fuel
I think the Kawasaki 10w-40 synthetic is the same stuff . The local Kawasaki dealer order's it in in the case for me . Turns out to be about 6.20 per at the discount if I am remembering correctly .
In my view it's a much better oil than the Castrol Superbike oil , Golden Spectro and a few other real synthetics out there .