Those Ultegra shifters - are they 7 or 8 speed? What about your rear cluster?

I ask, as I believe that's a 6400 RD - goes up to 7 speed (as delivered). I've never had luck with decent indexing on an 8 speed 600-series system with either the 6400 7-speed RD or the 6401 8-speed variant. Just curious as to what your experiences have been.

-Kurt