This is a great little silicone case. It offers protection with out being really bulky or awkward to use. Performance This case works very well. It doesnt get in the way of any function buttons on your phone and still protects the outer case from small scratches and drops. I dont think that it would protect your phone if you threw it against the wall but for day to day use it works perfect. Voice Quality This case does not seem to interfere with the voice quality during phone calls. It also does not interfere with speaker calls either. Battery Life I do not think that this case really affects battery life. I also dont think that you could use the extended battery with this case either. If you have the extended battery you may want to use a diffrent case. Durability This case seems to be very durable. It is silicone and has held up very good for me so far. Ease of Use This case is very easy to use. It slips over the outside of the phone and stays on very good. The silicone material is very stretchy which makes it very easy to put on. Design This case is very nice looking. I think it adds personality to your phone by allowing you to add color to your phone.