I like that kbin is smaller compared to some lemmy instances. I also prefer the UI. Bigger communities tend to feel a bit overwhelming for me. I also appreciate how transparent Ernest has been regarding kbin's development. That said, it's been a bit challenging to figure out how to utilize some of the federation features that kbin has to offer--microblogging in particular. From what I've seen, people don't generally seem too interested in this feature, but I think it's nice to have.