Thanks for the valuable feedback. Currently OutlookBar is still in its early stage and any feedback is highly appreciated. This way, we can determine the features OutlookBar will support in the future. Bringing the easiness of using PanelBar in hierarchical scenarios is something that we should definitely consider for OutlookBar.
It is difficult to determine which control is more powerful, since each has its strengths and weaknesses depending on the scenario.
Thanks for your interest and keep the great feedback up!
the Telerik team