I've been using this battery since receiving it 3 months ago, and I detect no difference in its performance vs. the original UTStarcom-branded model BTR6700 I received when I bought the phone over a year ago. I give it 4 our of 5 on the theory that if it performed in a manner superior to the original, it would deserve 5 stars; since it is in all ways equivalent, I give it 4.