I am a bit irritated the window to claim MWC as BTC owner was rather short, I simply missed it.
In theory MWC does not sound that bad, it is like Grin but they do use CoinJoin for all there transactions. Not sure how they implemented it, this is also a feature in the planning for Grin. There are some post from 2019 about CoinJoin’s but as far as I know non are actively in use right now:
I would not bash MWC since it is not a take the money and run scheme as far as I know, but MWC lacks many of the properties I love about Grin such as its linear supply to fairly distribute Grin and create greater price stability on the long run. I also love the great community and development team behind Grin. Probably there are community members who can better compare Grin, Beam and MWC on their properties.