>>ucario+(OP)
These days, I feel like this biggest obstacle with SAML is integrating with SaaS products. I've been in many situations where it requires back and forth emails to a support team. I've been handed a literal 204 page PDF on integrating with one vendor's SSO setup (the entire document was literally just for their SSO integration, nothing else). Attribute mappings are still a mess. It's wild how poor the experience still is.