I have swung both as well and you can feel a bit more endload on the 2013 over the 2012. Also they say they changed the bat a bit to add some durability, but tweaked it so it actually outperforms the 2012. The 2013 I swung had 100 swings on it and had amazing performance. Not near the feel of the very flexy senior Geezer previously out. The Senior One seems to me to have alot less handle flex and swings very smooth with little vibration. A great stick. I also bought some 2012's and that is a great bat, very similar and at a great price now. As a side note, for ASA I recently bought two RD28's and these bats live up to the hype they have as one of the best ASA bats for distance and performance. They too are different from the Geezer and Juggernaut ass they have alot less handle flex, and easy to control.