I just ordered my third Mantus. My first trip down the ICW in my 32 foot sailboat, I had a Delta and set a second anchor (Fortress) almost every night because of dragging during current reversals. The next year, with the Mantus, the Fortress never came off the foredeck.
The only complaint I have about the Mantus is how hard it can be to break out. However, if you were going to have an issue with an anchor, that would be the one to have. I have dropped it on 1:1.2 scope just to hold myself in place for a few minutes waiting for a lock or bridge and found it set.
On the sailboat, I almost always had to break it out under power. I always do under power now that I'm a powerboater (for obvious reasons).
A great thing about these anchors is that you can buy a humungous one and keep it disassembled in the bilger or locker for the day something like Matthew comes along.
I haven't found any kind of bottom where it doesn't work between Canada and FL.
I don't like their anchor roller but they are going to change the design next production run according to some ideas I gave them.
I have reservations about the security of their anchor swivel but those are easily relieved by putting it together with 5200 and planning to heat it up with a torch if you need to take it off the chain. It's a rugged design but depends too much on the light S.S. seizing wire to keep the cone from coming unscrewed.
I like their chain hook and have ordered another one for the new boat as well. You need to be careful in cold weather as the plastic part that is a belt and suspenders back up to it coming unhooked will break off when brittle. That doesn't compromise the strength and the hook stays on the chain much better than a standard chain hook anyway.