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.
I think - and please correct me if I’m wrong - that if you add items to the keyword box when creating a post/adding a link, your item shows up to mastadon users who follow that hashtag. I know that mastodon users occasionally interact with my links, and AFAIK that doesn’t happen with Lemmy posts.