I don't use glue but I have watched Dave Whitlock use a simple overhand knot with ZAP A GAP.  The knot held always.  I don't want to be bothered. I use a loop for most of my streamer/saltwater applications. Mako sharks, peacock bass, tarpon, bass....no more failure than normal. I believe the loop makes me "think" the fly has more action but one year while fishing for peacocks I experimented with regular improved clinch all week. I never felt I was not catching just as many...so who knows???