Well most reports on the reliability of connectors I have come from electricians who mostly do troubleshooting. I don't have any official statistics, but from personal experience I can confirm that any screw connectors tend to wear loose unless re-tightened regularly.
I think the differences between 120 and 230V to ground are neglibible as far as connectors are concerned as long as the current is the same - heat dissipation on a given resistance shouldn't change as power is R*I^2.
True, we don't have AFCIs (nor has anyone ever taken them into consideration I think), but they're a fairly new phenomenon in the US too.
Our RCDs are basically equal to GFI breakers if you only look at individual circuits (except for the higher trip current of RCDs). The widespread use of RCDs on all circuit does have the advantage that high-impedance ground faults trip the RCD, usually before they can cause a fire.
All that being said, I'd love to see how one would insert stranded wire into the new connectors without mangling it completely!
All connectors for stranded wire I've come across yet have levers that temporarily release the spring, allowing you to insert the wire smoothly.
