Red and green are the best, and for red, the reasons include cards weve already mentioned: Dockside Extortionist and Jeskas Will, but also Mana Geyser
Of the couple I know of floating around, either the stories have linked back to WOTC employees, or the card was shared anonymously leading me to believe they were the employee and wanting to avoid the attention
In Limited Cavern Harpy was a deadly card for the right decks, impossible to kill and giving you a lot of tricks to pull off
Funnily, my wife pointed out the borders being different sizes, but - unlike almost everything else about these cards - that actually happens to be a common issue with genuine Pokmon cards anyway, so I guess they nailed that aspect
Lastly, as with all other rebalances, players will not be receiving wildcard reimbursement for these changes