This is one of the better articles on testing anchors but it is hosted on Peter Smiths website so obviously he selected a test where the Rocna performed well. They do perform well for a roll bar anchor but the rollbar limits the depth the anchor actually penetrates sand. The Spade and the Ultra on the other hand just keep going down! Rocna have their take on a spade anchor with the Vulcan.
I'm in the spade type anchor camp and I think they have the larger surface area for holding than any plow anchor. The Sarca Excell has the added wings to try and get the spade performance.
The down side of the Spade and the Vulcan is the shape of the shank which does not fit easily on a bow roller. The Ultra has a very similar spade as the Spade but the shank is almost identical to the Rocna so it fits on a bow roller. The Ultra is only available in polished stainless steel and is very expensive. It's also the most stolen anchor in Australia and the owners of the gin palaces just replace them with Sarca Excells!
Another anchor to consider is the Bugel. These are the first of the high-holding anchors and come standard on all Amel yachts.
Anchor resetting is a major concern for most people. Anchors that reset quickly are those that have the most weight on the point compared to the other contact points, the end of the shank and the corner of the wing. There is a Youtube video somewhere comparing the anchors.
I use a copy of an Ultra in SS that I fabricated with a hollow shank that concentrates the weight in the lead-filled point. Total weight is about 13 kilos. I can not recall the weight now of the three corners.