I recently installed a number of PorterPorts, but I also had an opportunity to compare then to some P&S duplexes. I'd have to say that each seemed to have excellent grip, and were about on par as far as that goes (based upon my very non-scientific observations). However, the Hubbell seemed to be a tad better quality as far as the connectors and contacts, though. I can't imagine either of them having a problem holding onto any plug. In fact, it can be somewhat difficult to get certain plugs out, they grip so hard!
Tom.