Follow on to my last post for what it's worth
My 550 XP Mk1 arrived yesterday.. power head did weigh 10.8 (my scale has it just under 11).. with full fuel, oil, and the 18" bar it weighs 14..
I also have a 440e .. power head only is 9.7 lbs on paper.. with fuel, oil, and 18" bar it weighs 13...