Disclaimer: I work for Google, but not on Cloud.
Zoomdata is a good alternative, but pricey and not mature enough I feel.
PowerBI is getting surprisingly good, and if you're a Microsoft or R shop it can be a really nice fit for the price. I've thrown a few 50GB+ CSVs at it. It's basically Excel on steroids. If you're dealing with some data stores (like mongo, elasticsearch) then PowerBI isn't viable natively.
Interesting to note that zoomdata and tableau use spark under the covers iirc.
[0] https://www.tableau.com/products/coming-soon
[1] https://research.tableau.com/paper/analytic-data-engine-visu...
Its got its share of flaws and issues, but for the price I think it beats everything else on the market - especially for existing Office365 customers.
Maybe it is better to use Python Pandas or R interactively to know more about your data.
In the beginning Power BI started out pretty weak compared to Tableau, but over a couple years they make huge investments and seem to even be ahead in some areas. For example, it used to be Tableau didn’t support 3rd party or custom visualization, although I haven’t checked recently if that’s changed.
So much development effort is being poured into many of these competitors, any useful comparators have to be pretty new.
[0]: https://cdn2.hubspot.net/hubfs/2172371/Q1%202017%20Gartner.p...