Thing is Arrangers are not (And never have been) designed for professional working musicians but the home hobby player, hence the complex style to make them sound great without the wait. (There basically more advanced easy play features of the home entertainment organ)
For me personally I have always found Yamaha styles to be the worst out there as they are mainly song specific, Korg as you say are very live sounding and are like you have session musicians backing you, but for me, give me Roland styles any day of the week, as they are great whether you use an arranger keyboard or an organ where you do most of it yourself.
There is no right or wrong as each player has their own preferences

Bill