I just needed the possibility to "preselect" the "Filter"-Checkbox and the filtered Column in a Multicolumn-Combobox. So I worte an Email with my request, beeing used from other providers to get wishes like this solved in one of the next builds. Usually, I waited for this for - let's say from one year to eternity.
Sundar answered within one day. He promised me help within a week.
To my absolute surprise, after one week everything I wished was solved (also some other stuff in the panel bar).
Great work. Great guy.
And I think, I am a lucky guy to have bought these tools.
My recommendation: buy and hold

Outstanding support and controls. Sundar has always walked the extra mile of educating our team about Wpf and the controls and not just answer with one word answers. We greatly appreciate his commitment and intend to be his long term customers.
Thanks
Navin