Tableau is an absolute leader in Self-Service data discovery BI. However, MicroStrategy hugely invests in Desktop in order to be on the same level with Tableau. According to the magical quadrant 2016, Tableau is an absolute leader in self-service BI. According to my experience, MicroStrategy is the best in the Enterprise BI. If you are thinking about what tool to use, it will depend on the business case. If there is a requirement for a huge BI platform that should be scalable and have strong security then go for MicroStrategy. If we need quick results, agility, and flexibility then go for Tableau. And we should remember the latest trend in BI - use bimodal models. For example, we should give opportunities to users which have strong governance and a centralized BI platform with self-service data-discovery agile BI.