I haven't tried Ultimate, only normal Unleaded, Optimax and Sainsbury's Super (I reckon you should have had all of the "super" versions in your poll). Unleaded gave me the worst economy but performance wasnt affected by too much, optimax is definitely better than unleaded with better economy too but Sainsbury's Super seems to perform the best. Pulling cleaner in the lower revs with the same economy as OPtimax and its cheaper too.