First off is the mana. The new Gideon has a converted mana cost of 4 while Gideon Jura's is 5. Then is the abilities; the new Gideon can still change into a indestructible human soldier, but he isn't restricted to a 6/6. Gideon Jura will destroy many of your opponents creatures but that can not compare with new Gideon's ability to destroy all permanents. While your opponent is still recovering, Gideon, Champion of Justice can become a human soldier and destroy any opponent.