I've been using the 0x router since we started @ripsapp and its honestly an amazing API - fast and usually quite efficient - backed by a great team (very responsive!). That being said, we've been running into issues with some tokens having high sell fees - something we try to avoid as much as possible. With this in mind, I'm expanding our token system to support multiple routers. I've been testing kyberswap and its pretty good at filling in the holes where 0x seems just a little blind. It will be a small improvement, but one that will let us work with more tokens as we continue to expand the Rips-verse :D