I prefer the ones with set screws and a collar to keep them from backing out. They are much better than these at retaining the wire. I've tried a lot of these things. I have dozens of them laying around the house.
PE sells some that have an extra piece inside, a "bullet", that helps retain the wire without cutting into it as you tighten them if you use the side entry - 091-330. Those can still come loose like these though. They also don't go on sale for 98 cents.
It doesn't really make any difference to the sound.