Well I use a mooncup and it’s been really, really great for me and I’d certainly recommend it.
The best part for me is that I have such a heavy flow I can leave the cup in for a good few hours at a time, whereas before, when I was using tampons, I’d have to change them every 45 minutes on the first few days of my period.
I’ve never personally used sea-sponge tampons so I can’t really offer an opinion on them. Sorry.