Anyone have comments on how this might stack up against AG-Grid?
AG-Grid focus's on being a fully functional spreadsheet where as tabulator goes more down the route of interactive table.
Tabulator has a publicly visible development roadmap so you can see roughly when new features are going to come online.
There is a new release every month or so, so if there is a feature you feel you need you can create an issue on GitHub to get it added to the roadmap.
Most importantly, Tabulator is FREE even for commercial use!
I am VERY excited to start trying to use this instead.