A:Answer I have the 2 last models, so I wil compare them for you... Second model: SKU: 5496202 VS Third model SKU: 4388800 (I purchased both)
Sound:: the second model has a better sound quality than the third model, the third model sounds a lot louder than de second model (But with less sound quality), the second model has 3 speakers, the third model has 2. Both are very good with the battery, the secret is not using it at its top volume. The second model shuts down at 10 minutes of unuse, the third model DO NOT TURN OFF AUTOMATICLY becouse its power button is not digital. The second model has a beautiful sound when it pairs and unpairs, the third model has has a awfull speaker "bop" when it interacts with your phone.
Actualy I would like the third model to be remodeled and make it more similar to the second model. They focused on the battery, water proof, and volume, but they forgot about the sound quality and interaction experience.