I have had them both and I think the kole is harder to keep, They are much more active than yellows and constantly pic and graze the LR for food. Their bristeltooth mouth makes it more difficult for it to feed on some foods than the yellows can and can injure the mouth easy. They move much faster and cover more space thru the day than the yellows. I dont think the kole can take stress related issues like temp changes or water problems, ect. as easy as yellows. I think the Kole needs a larger tank than a yellow only so there can be more space and LR for it.
JME.