After having the x2's, the sound is a huge improvement! Additionally, the Jaybird application allows for adjustments of the sound of the earbuds, even providing some presets for various genres of music. Battery life is about 6-7 hrs, but does use a different charger than the micro USB of the 2's. Finally, the range is a definite issue if you plan on having your device away from you more than 25-30 feet. The x2's provided me a range of around 60 ft, allowing for me to move around the gym freely. With these, if I plan on going away from my rack, I usually have to take my phone with me.