I recently compared Qlik, Power BI and Tableau as a reporting system for our customers. I would say Qlik was the most eager out of the 3. They got me in contact with their OEM team and were very forthcoming with information. Microsoft gives you all the information you could want up front. Tableau never responded.

Power BI also has Power BI embedded for Azure services which bills report views on a per session basis. This might be what wins me over to Power BI if it makes financial sense.

R also has https://shiny.rstudio.com/ which is pretty neat as well.

In the end we would like our small/medium sized customers to build on top of this platform so we will probably stick to one of the big 3 rather than completely roll our own.