I used Syncfusion WPF controls (GridDataControl, GroupBar, TreeViewAdv, etc) and they are really easy to implement. The samples that were included also helped a lot especially when using the controls for the first time or when implementing an unfamiliar feature. Best of all is the support for bug fixes, implementation problems and questions. They always respond immediately to user inquiries. Their incident tracking site is also very helpful especially for large teams where users may encounter the same issues. I highly recommend this product!