You know what's wrong with megas? all of them get a flat 100 BST increase. So you get pokemon like Tyranitar with BSTs higher than box legends, and you get pokemon like Pidgeot or Glalie who are still sub 600. Ironically pokemon that receive megas like Beedrill and Sableye actually turn out better than middle of the road pokemon like Camerupt because Gamefreak has to minmax the everloving hell out of them.

Honestly I think megas would be more interesting if they didn't get a BST increase, just a type or ability change and BST rearrangement like Scyther and Scizor, coupled with the ability to use items.