I have stopped today using ADDT since it was discontinued. I'm moving to WA.
I'm really happy to hear from you that WA will do some kind of ajax datagrid similar to InterAkt NeXTensio lists. NeXTensio was the most important and popular extension from InterAkt, I would really pay hundreds for something similar.
By the way, the the last Kollection 4 Beta demo was supposed to be using ajax.