1. If you want a keyboard where everything is done for you, and you are happy to accept what the manufacture supplies for you, then a closed keyboard is the way to go.

2. If you want to do your own thing, use the sounds and software you want, are prepared to put the work in and never have to buy a new keyboard (Just update the Hardware/Software) then an open keyboard is for you

To sum up

OOTB experience, go for closed

Do your own thing, go for open