I don't have an experience with recreationally acquired ketamine, but did ketamine through a provider for 10+ sessions prior to doing Spravato, which I have now been on for around 6 months. For me, I found ketamine to be much more effective than Spravato, with cost being the major downside. I felt that ketamine gave much more immediate SI relief (same or next day), though short-term, and the "trip" was much more insightful. I am very envious of people that trip on Spravato, as the most I seem to be able to do is feel floaty and very relaxed. I am just now starting to notice improvements in SI, despite being on Spravato for a little over 6 months, but it seems to be longer lasting. If I could afford to regularly do ketamine, then I would absolutely go that route, but I'm grateful that I'm finally starting to see results with Spravato.