I have been trying out a few of these Efest batteries, and have some more sizes on the way. They look pretty good quality.
Here is a comparison of the Efest IMR 1500mAh and AW IMR 1600mAh and Sanyo Ur18650W2:
Here is a comparison of the Efest IMR 1500mAh and AW IMR 1600mAh and Sanyo Ur18650W2: