Mostly that i can sort things however i see fit ... that is HUGE plus for me, since i have a little deviation in this matter, i hate autosort and believe that person who maded is should burn in hells. :-/
Also when i do (and if they stay that way

) its much easier, and faster for me to orient in that UI ... personaly i use hotbar in Heroes of Might and Magic aswell, for the spells i use most often ...
And for the third time (is that the expression in english too?) im used for hotbar, many games i play ses them so ... its more friendly for me, than lear to orient in something entirely new with every single game. :-/