All 4 are uniquely good in their own way, with the player, setup, and recording settings being a contributing factor.
Overall rating based on this video, for me:
1. Yamaha, with better right hand sounds.
2. Keytron, style is definitely top shelf stuff.
3. Korg, overall balance is near perfect
4. Roland, for a 20 year old board, still sounds good.
Very subjective, and with some editing, one can make the necessary adjustment to achieve a desired sound.
Happy Holidays SZ