Migrated to plasma 5 environment last week (arch), found most of the things I was used to in KDE4 workspace, exept the option "open wallpaper image" on the desktop when using slideshow. I use slideshow to "slide away" in a gigantic photo-collection, and often there is the urge to open the image and containting folder of a long-time-no-see photo...

No show-stopper at all, but one of the things which made me choose for KDE some years ago...

You may want to file a wishlist request on bugs.kde.org.

https://bugs.kde.org/show_bug.cgi?id=343854

thanks for this suggestion, should have been obvious to me

And it's been fixed now, so Plasma 5.3 (out in about 3 months from now) will have it.