Use who you feel like you can win with. Even top players rarely solo main throughout an entire tournament.
My Ike is just better for me for pretty much every MU atm.
I like to use Pika but I can't kill with him outside of thunder gimmicks. I like to use DK but I get juggled too much to use him. I like to use Jiggs but for now I'll use her in MMs since my Ike is better in most MUs.
MK is pretty much the same as my Ike, but less consistent due to dying all the time and less proficiency with MK than my Ike.
My Ike is just better for me for pretty much every MU atm.
I like to use Pika but I can't kill with him outside of thunder gimmicks. I like to use DK but I get juggled too much to use him. I like to use Jiggs but for now I'll use her in MMs since my Ike is better in most MUs.
MK is pretty much the same as my Ike, but less consistent due to dying all the time and less proficiency with MK than my Ike.