Yes, I've noticed this. just bought a few Crabtree sockets for an office conversion (to fit in with the existing style in the house). It's because they've started fitting the Volex guts to the Crabtree face plates to cut costs.As you say they are rubbish compared to how they used to be.
Electrium (headquartered in Walsall iirc) are very cagey about where any of their stuff comes from (Marbo, Volex, Wylex, Crabtree, Appleby)
I've even gone off the Appleby metal back boxes, because I've noticed they come out of the packet greasy and dirty. They've obviously stopped the degrease and wash at the end-of-line to cut costs. Not so bad on a dirty rewire, but is a nightmare when you're putting in extra sockets as the grease and dirt (incl swarf) transfers to your hands and then to the decor. Even had a metal splinter off one.
Could we complain to Electrium as a group? Maybe put up a "petition" on the forum and then once "signed" by enough of us mail it to Electrium sales? X(