I don't see much better grip from a duplex outlet than the top offerings from Hubbell and for a fraction of the cost Pass & Seymour. I use both and frankly I always recommend 20 amp P & S's with the clamping from the back to the wire for thirty plus years and everyone I've checked is still very tight. When I added P & S (now discontinued) Grey/ clear body colored ninety degree male plug to the end of a power cord, the two gripped like a permanent bond. To this day they hold well as a recent visit to an acquaintances home where I did this in the early 1990's. Still my fav right angle plug if you can get them that was reasonably priced.
Good outlet for amplifiers
I have a circuit in my listening room for my amplifiers and it uses a dedicated ground. Right now I have two duplex outlets connected - and I use the primary outlet (first on the run) for the amps (reserve secondary for subwoofers if needed). I would like to install better quality outlets for this - two duplex, set up for a dedicated ground. I could see spending $100-$200 per duplex, if that gets me something decent. I want it to grip the plugs well. Recommendations?
PS - I'm running two VAC Phi-200 amplifiers (200w tube amps, KT88)