I think what Brenner is trying to say is that ____fire companies lie about specs. OEMs have real specs that you can use as a starting point when calculating what current to set your power supply to, and therefore are safer to charge with a PSU. Obviously, charging with a PSU is the best way to charge known, unprotected, single cells if the user knows what they are doing.
Other things to take into account are how many cycles you have put that cell through, how old it is, what its internal resistance is, has it ever accidentally been dead-shorted, etc.
Kind of like when you buy a <5mW laser from ebay. at levels below 5mW, total radiated power in the beam is low enough that your natural blink reflex will block the beam before it has a chance to cause damage to your retina. This doesn't mean that you can wave around any laser labeled <5mW all willy-nilly, for all you know it may be outputting 80mW.