When I am in the bookmarks section of Dolphin, the mouse wheel scrolling is slowed down significantly.
One step is about 4 pixels. It is the only place where this happens. Can somebody confirm that?
This is an old bug fixed in version 16.12.1 of dolphin.
Can I somehow get this version of Dolphin without de-stabilizing the whole system ;-) ?
It will come in our next update of backports repo.
If you really need it you could try activating the testin-neon repo and specifically only update dolphin. Though I am not sure if it needs the newer qt5.7 version aswell. Just try it out and disable that repo again if you don't want all the other stuff to be updated.
phewww.... shivering ;-) Maybe I will better wait for the next update... It is not that urgent!