Hi,
I have been using A123 batteries from Electro-Dynamics for about 3 years, I run two 2300mAh batteries in my jets and single 1100mAh packs in smaller sport planes.
I am charging with Cell-Pro chargers, I recharge the batteries after 3 flights. Each 8 minute flight takes about 300mAh.
I have never used Dura-Lions, so i can not give you the differences, I would not be afraid to try the A123 batteries.
Good Luck.
John