In 2014 if you clicked on a part, which is in a subassembly, the components list updated itself, and highlighted the actual part (opening the subassembly):
In 2015 this doesn't happen, only for parts in the main assembly:
Further, if 2014, regardless if you single click (w/o ctrl) in the model or in the component list, only one part is highlighted in the model and in the component list.
In 2015, you can do the following: single click on one part in the model and single click (w/o ctrl) on another part in the component list - two parts are then selected, which is not what should happen:
If you first click in the component list and then in the 3d model the expected behaviour occurs.