The decision to move away from a desktop based Dashboard Designer to web-based only is a huge mistake. I became interested in Syncfusion because I thought it would be a contender against PowerBI - it certainly seems to have features that make it superior.
Except for Dashboard designer. Which frankly is terrible. The web-only design is a ridiculous choice. It is so slow I have to wait for spinning circles even when loading sections of the editor, not even the dashboard itself. Which would never happen in a desktop app. And if I attempt to load any serious amount of data, the tab in my browser crashes due to timeout. I am guessing it is also limited to 32-bit in the back end, because it also runs out of memory during data loading large data types (e.g. geometry).
The website advertises the product as being able to connect to multiple data sources. But it can't, it can only connect to 3 flavors of SQL server (which isn't a problem for me, but clearly false advertising).
I don't have these problems with PowerBI which actually works properly. Even if data loading takes a while, at least it loads. And the interface isn't laggy.
Combined these things make this a useless product, and not even close to being a contender against PowerBI or Tableau.You've essentially taken a potentially great looking product and made it totally worthless. Good job there.