Yes, definitely problems federating, kbin.social is under quite some load and I made a new kbin instance (I'd previously only been testing). It's been up over 2 days and not received a single thread or comment from kbin.social. In the meantime it's filling with content from lemmy instances, like this thread for example.
But, I'm sticking with kbin for a few reasons. First as you say it's a younger project and things will only get better, and as a software developer maybe I can help with that some. But, also because I like how it looks and prefer it over others.
I think there's a lot of functionality missing, but it's going to come over time. For people not prepared for this kind of bleeding edge operation I'd certainly not blame them for wanting to use a more established project.