I've only worked with a tiny handful of old ones an electrician left at a new construction site. I doubt you could get stranded into these, you have to push the wire in with quite some force. Also I wasn't able to find out how the release mechanism works, so I only use them for connections I think I won't ever need to open again. I don'T like things I can't figure out how to use, thus my deep mistrust of any connection that works without screws. I only use choc blocks. (And just for fun I recently bought a bag of wirenuts). I also don't like plugs with a casing that snaps shut (quite popular cheap type of Schuko plug).
All recent receptacles with screw terminals are backwired. Light switches and some plugs have been backwired almost forever (I've got an early 1900s backwired rotary switch). There are several types of terminals used here: the typical US side wired style where you have to wrap the wire around the screw. Then perhaps the most common style, a simple screw but with walls on 2 sides that keep the wire from sliding out when tightening the screw. then there are the types with pressure plates, sometimes simple phase/neutral screws and pressure plate for the ground, pressure plate terminals are always rated for 2 wires. And then the last type, a solid metal block with a hole in which you push the wire, then tighten the screw. Very popular for plugs, old light switches use it as well.
I usually buy Kopp at the hardware store, they seem to last. Or I use salvaged stuff, mainly made by the Austrian companies Maté, PE and MPE (now all Legrand), very reliable stuff.
Older german receptacles are weird, they usually have 2 individual ground screws, one for the incoming neutral and one for the jumper to the neutral screw, an easy way to tell apart German and Austrian.
