I assume they mean that you're going to spend many hours with characters you don't give a shit about (and don't know how to play, and can't equip with your OP gear) fighting against other characters you don't give a shit about with combat that kind of doesn't work well in in MGQP
I felt that way for a while but some of the characters started to grow on me. The guy from SHRIFT (which I had written off as edgy teen deviantart bullshit), Rigeo or whatever her name is, Hakuna or whatever his name is, and the guy from parade buster were all pretty decent. I actually liked the dude from SHRIFT so much I might download that game sometime.
Note that you do get some pretty strong characters out of it though, but not having enough characters to use isn't an issue you could ever have in this game.
BUT WAIT there's more. You get to do it all again, run through the last dungeon again, do some coliseum fights again, and now you add the villians of the collab to your group. Strong characters though, some of them actually legitimately busted.
BUT WAIT there's more
again. Because now you can do a
event that can take quite a while if you bumble through it without reading everything. And again it's based on characters and events that you don't care about.
So yeah, the collab is a mixed bag. Some of it's good. Some sections are bad. Sometimes I wish I could leave and come back, but for the meat of it, the first and third events, you're stuck until you're done.