It would be nice to have the option for a single filter input that searches all columns on the Grid. I was able to implement my own custom solution but having to apply that to every grid in my app is cumbersome.
I understand the importance for the flexibility side of having each column with its own filter box, but for simpler apps this is overkill and a single filter box is enough. The column component already has the [filterable] flag so this can possibly be used to exclude any columns if necessary.
I was thinking of something similar to what is an out of the box feature for the Datatables JS plugin
Default search box that searches everything. Very simple to use and understand for basic users or when your application only calls for something that simplistic.