I have been thinking about getting some kind of official validation of my cognitive abilities and I keep going back and forth between pursuing Mensa membership and taking the RIOT IQ assessment. They seem like they serve different purposes but I am not sure which one gives you more useful information. Has anyone done both and can speak to what each one actually offers?
They are genuinely different things and comparing them is a bit like choosing between a trophy and a medical checkup 
Mensa membership tells you that you cleared a single threshold, top 2 percent on an approved test. That is it. You get a membership card, access to a social network of high IQ people, and the ability to say you are in Mensa. What you do not get is any information about your specific cognitive profile or where your strengths and weaknesses actually sit. RIOT IQ gives you the opposite. It is not a social club, it is a 15 subtest assessment across 6 CHC cognitive domains that produces a detailed profile of your fluid reasoning, crystallized knowledge, working memory, processing speed, and more. If your goal is self knowledge and understanding how your mind actually works, RIOT IQ is more useful by a significant margin. If your goal is a credential to mention at parties, Mensa wins that one 
Mensa is a destination and RIOT IQ is a map 
One tells you that you arrived somewhere, the other tells you the full terrain of your cognitive landscape. Depends entirely on what you are actually trying to learn about yourself