Been using several of these connectors for a couple of years for my keyboard rig (keys, racks, amps) rehearsals and gigs. Never had a failure, breakage or poor contact, plugs still fit nice and firm. Set-up looks cleaner because they don't reflect much light. I'll be buying a few for my co-players, because they can't seem to leave them alone. Missed earthing occasionally, but knew what I was buying.
In short: they're inexpensive, do the job and seem to last.