So, to be clear - every model I have used in the past, the slow cooker did not work well. I’ve had 4 now, with the 8qt Pro being my current model. I have not bothered to try it with the 8qt Pro as it performed poorly with the other models. Additionally, my other models were 6qt and round; I prefer a larger, oval crock for slow cookers.
IMNSHO, the reason the IP does not work well as a slow cooker is inherent in its design. It has a relatively thin, stainless steel pot that heats from the bottom via an element and additional piece of steel on the bottom of the pot (helps to distribute the heat). Slow cookers have the crock and heat via a band around the sides. I feel both heat distribution and retention are simply superior with this design and, during my earlier attempts to use the IP as a slow cooker, I found this to be the case every time.
I’m one of those types who believes in using the right tool, as designed, for the job and the IP was never really designed to be a slow cooker; it’s not among its core strengths. The same can be said for air frying.
So…that is the basis for my position on the slow cooker function. Either way, I still would recommend the 8qt pro model as the best-in-class model of IP and a worthwhile purchase. I use it for a variety of tasks - soups, meats, pasta/rice dishes, hard boiled eggs, rice, thawing, bone broth, sous vide…it is one of my kitchen workhorses and key to keeping our home cool during the summer months.