The RadSlider supports the "increase" and "decrease" handles, but "decrease" only decrements SelectionStart, and "increase" only increments SelectionEnd. Ideally there'd be an option for *two* sets of buttons at each end of the slider, an "increase" and "decrease" pair, so that both SelectionStart and SelectionEnd could be *either* increased *or* decreased independently. See the attached illustration. Thanks! 

There is IncreaseDecreaseHandlesOnBothEnds SDK demo available since R3 2016 Release.
https://github.com/telerik/xaml-sdk/tree/master/Slider/IncreaseDecreaseHandlesOnBothEnds

Expose an easier approach for styling the buttons that are placed over the slider's track. For example Style properties. Those RepeatButtons have their x:Names set to "LargeIncreaseHandler" and "LargeDecreaseHandler". 

Currently, in order to modify their appearance (like Background for example) you will need to override the entire ControlTemplate of RadSlider.

In the default control template of the RadSlider, the Track element is represented by a ContentControl control. When using the Xaml version of the assemblies, it would require extracting the TrackStyle, in order to base the custom one on it. An alternative would be to use the ChildrenOfType method to retrieve the ContentControl with x:Name="Track" and apply the needed modifications.

Both of these approaches could be a bit overwhelming when only the Width/Height properties of this Track element would need to be updated.

We could expose additional properties for changing the Width/Height values of this ContentControl (x:Name="Track").

When the slider is hosted in a TabControl its bindings don't work as expected when switching tabs

Fixed in Q3 2014