I haven't anything good or bad to say about Mantus or Mason anchors, because I haven't used them. I couldn't care less how many times I am shown "test" videos in various bottoms. I don't care who was first, last or somewhere in between, in the development of my anchor.
I care about my boat staying where I anchored it, with as little fuss as possible, no matter what the bottom is, in any weather I encounter.
It has been 2 years now, that our Rocna has done just that. So far, maximum gust has been 65 mph. How many times have we done doughnuts as the wind shifts after a squall? I don't know, but the Rocna has not moved more than it's own length, as far as we can tell. I'm talking about over 700 days/nights at anchor, in that time. In sand, hard mud, loose mud, on flat coral covered by a few inches of sand, in weed and I really don't know what else.
I'm not trying to sell Rocna anchors here, but folks these things do exactly what they are supposed to do, very, very well. The galvanizing hasn't come off at all (unlike my 8 month old, US made hot dip galvanized chain), nor has it bent and our boat weighs something like 77 thousand pounds. I don't have to back down on it and I never have to reset it.
I am overjoyed that those with Mansons and Masons are happy with them, but really, I think the Rocna is just fine, too.