Benfits of upgraded connectors

Yes, indeed. No connector is better than any connector. We use connectors because they make life easier, not because they improve the sound.

I agree with Stringreen. The connectors have a large impact on how a cable performs, and many times it is the connectors that affect the sound more than the cable itself. The best connector is no connector, but not very practical. There are many other variables that will determine the actual benefit to a system, but in general better connectors will sound better. Lower resistance, better conduction, different alloys. etc.

Can you hear the difference between silver and copper?

You guys must practice this. ;-) I don't disagree that I can not hear any difference between chassis mounted connectors, and no doubt there is a lot of bullshit, over priced accessory items. There is benefit to buying the $5 set, rather than the $3.50 set only in that they grip a little tighter and don't corrode as fast. But on a cable? That, IME, is usually easy to hear because in the least the connector is a resistor in the path.

Try it yourself if you're into diy. You can make an IC from solid strand copper magnet wire, or silver. Also get a pair of copper and silver ends. Swap them around and see what you think.

Or, keep reading what someone else tells you to hear.

Well, I admit I don't know exactly why they sound different. But I do know that I can easily hear the removal of a 4 ohm resister from my crossovers, and removing connectors is an even greater change in clarity and depth although they measure much less than 4 ohms.