Factors to consider, the Phenom II's K architecture is really old, basically AMD flogged it for to long but the upside is for its time it was a mighty efficient chip and at a good price point. Today it still is a good processor but it has been effectively replaced.
The Core I architecture is much newer and more power/performance efficient but that is at times a very overrated factor when it comes to gaming rigs. While I am sure there will be a bazillion and one synthetics out showing the i3 to be the most amazing gift to planet earth, frankly there really is nothing decernably different.
On this one, the i3 will run cooler and efficient but you are basically rocking a retro dual core with a last hoorah.