Here's my opinion. As the jig is pulled through the water, having a "loose" tie at the eye allows the jig to swim with a more free style action. This in turn seems (to me) to generate many more hits than a tight line tie. That being said, I do not trust a loop knot, mainly because of the abrasion inside the loop by the jig eye. Consequently, over many years of trial & error, I'd settled upon "snap clips" which are tiny metal clips that fly fishermen sometimes use. These are available from Netcraft and other distributors on the internet.
Tying a Trilene knot to the the clip eye allows me to switch jigs easily and efficiently. And, it allows for total freedom of movement for the jig's swimming action. JMO Folks! The most important thing is that whatever attachment or equipment you use, that it gives you the confidence you need to be successful.