This mp3 player is easy to use, has great features, and is excellently designed; however, I would not rate 'very good' because on several occasions it will just freeze and 'lock up.' After this happened a few times and I couldn't figure out what to do, I finally found the answer that all you have to do is hold the power button down for 15 seconds. SO this is a very simple solution but it is annoying on the several occasions this happens. Sound Quality I think the sound is great; I never have the volume all the way up but if you really like to "rock out," I'm sure it would be great for you too! Performance As I mentioned, the performance is great most of the time, but overall I would not rate it as 'very good' because multiple times it has completely "froze up." This was very irritating before I figured out the simple solution, but I still don't know why it does it in the first place. Battery Life Excellent! I know for a fact the battery life lasts more than 14 hours! It is great. Durability It's very durable; I know I have dropped it a few times and there is no damage to the interior and hardly any to the exterior! Ease of Use The easiest to use mp3 player I have ever owned! It is very clear and easy to use all the features. Design I love the design! It's the perfect size for me, very small but not extremely tiny.