There are a couple variables here.
1] Are you going to buy a dedicated GPU?
if so then the 2100 is the way to go. if not then the APU is a definate consideration. If possible look more to the A8 and to be released A10.
2] With a APU you lock into a specific socket that has no future proofing.
while a 2100 can be put onto any H61/H67/P67/Z68/Z75/Z77 chipset motherboard, which gives you a better upgrade path.
On pure compute power the i3 is stronger than the Llano, but if you are running on integrated graphics then the llano is stronger, considering not many big gaming titles support intel HD2000