Primarily Yamaha users are happy with what they are given by the manufacture, or what is available from others online, whereas Korg users like to do their own thing and sound as they want, rather than playing along to what someone else has produced.

Comparing the 2, the Yamaha is more versatile if you want to sound great with minimal effort, (Even if it isn’t your own work) whereas the Korg is more versatile if you want to achieve a more individual sound and performance.

As per usual, you pays your money and makes your choice

Bill