Boring, grindy, unfun. The raid requires not only a huge amount of time, but it requires intense attention to do properly, even when you should be massively outgearing it, simply because of the annoying mechanics.
I don't mind when things are hard but here...
a) Can't do anything because you are pigeonholed into a few teams due to them being immune to almost everything
b) There is a huge random factor involved sometimes that makes you need to restart and do it again
c) The raid is too complicated for a mobile game.
In my guild people barely do it, and I see more players quitting now than at any point in the past year. I can't blame them, this raid is bad, and increasing the rewards isn't going to make it better.