The performance of the property grid isn't great, and it appears that the performance degrades on some scenarios.
We are placing the property grid inside a RadDocking. The pane itself has the IsHidden bound to a property, since the software is an IDE and depending on the type of the active document, we either show a toolbox and / or a property grid.
I can see with dotTrace that something is leaking (The weakevent listener is raising the handler more time than it should).
If you click the first button and then the second button over and over again, then you would notice that the property grid becomes slower and slower, and that the Telerik.Windows.Data.WeakEvent+WeakListener`1.Handler() is being called more than once, event though OnCollectionChanged was called only once.
On Telerik 2016.Q2 the problem was even worse. The OnCollectionChanged would be called as the number of properties the object has.