I like the backstab ones that are held in place by the screw rather than a spring. It's the best of both worlds. I've only seen them on GFCI outlets, but apparently they're on "industrial grade" outlets too: »www.handymanhowto.com/2011/01/17···ck-wire/
Technically called backwire, totally good. Backstab, where spring pressure hold the wire, is not reliable long term.