I liked Riddlers and Chang, I don't even remember Mantis or Vortex GA enough to have an opinion about it, Vortex at Carowinds was no bueno, and whatever that Togo one is at Kings Dominion can burn in a fiery pit of despair.
I really like the thematic costumes they're giving the characters, especially Donaldo. Looks good, hadn't heard anything about this addition but seems like a fairly impressive addition for what it is.
You do have to factor the further into August you go, the busier it gets, as people rush to get in trips they put off the rest of the summer, before school gets back in.