Meagan Longoria has an after-action report of a proof of concept using Power BI Report Server:
In addition to managing to versions of Power BI Desktop, I also found myself mentally managing two sets of features. I was constantly asking myself “Can I do that in Power BI Report Server?”. Some of that is because PBI Desktop for Report Server is on a quarterly release cycle rather than monthly, so I had to remember if a feature I wanted to use was new (or in preview) and therefore not available in this version. The other part is trying to remember what you can and cannot do with a Live Connection. For example, you can make report measures, but you can’t use ad hoc grouping and binning.
We had several scenarios where users wanted to be able to group fields in multiple ways that changed somewhat frequently. Since we couldn’t use grouping and binning in Power BI Desktop to accomplish this, we set up an Excel data source in the SSAS Tabular model, and allowed users to change the groups there and refresh the Tabular model when finished. This could get rather unwieldy if you had lots of users who needed this kind of flexibility.
Ultimately, the customer considered it a success. Read on for more details.