From the Yellowstone Tippet Shootout:
"The Davy knot was developed for one purpose – speed. In fly fishing competitions, lost time means lost fish, and often lost competition. Once you practice this knot it can literally be tied in a few seconds. Once your muscle memory is trained, you can even tie the knot without looking at it, allowing you to watch for rise forms. It also uses up very little material. Like the Orvis knot, when you pull this tight there is less friction.
The only problem we found with the Davy knot was its knot strength. Reportedly, it is supposed to test nearly 100% break strength. Our data revealed it breaking strengths to be reduced by as much as 40-50 percent. For example, Rio Fluoroflex 2X has a straight pull break strength of 11.19 pounds. After averaging 6 Davy Knot breaks (or slips), breaking strength was reduced to 5.32, which is roughly 52 percent weaker.
Bottom line: This knot is super fast and wastes very little material, however it tested weaker than a wind knot. Unless you are in a competition where time is of the essence, (or fishing to 8 inch trout) it only makes sense to pick a stronger fly knot. "
https://www.yellowstoneangler.com/gear-review/tippet-shootout/