I have had people ask my "why should i pick Spade over all the other anchors". I found this YouTube channel SV Panope, and this person independently tests various anchor in different conditions. He uses video cameras in the water to show how the anchor perform as well.
He created this 40 minute video comparing several different anchors and anchor types. It's really a fascinating video and worth the watch, but at the end he concludes that the Spade anchor is his go-to anchor.