Yes, I'm talking about these:

I got one free with a new jackplate (Strat) today, and was wondering if it was worth putting it in - my current one is off some Chinese piece of crap.

So, does the jack have any effect on sound, or sound quality? Would this new jack be better than my Chinese one? Or are all jacks the same?

It's probably the same(ish) still mast produced, more than likely in china.

Unless your current jack give's you a lot of crackling noise and is slack, then i would just leave it. It doesnt effect sound, it does effect sound qaulity, but only to a certain degree.

I'd just keep it in a draw incase you ever need it in the future.
Black Knight CF-60F Semi-Acoustic.

Black Knight CP200 (Red flamed maple).

Neck-thru 4 string bass.

Acoustic 6 string.