The EGO is popular for a reason. Its a solid little unit. Ive used many. But I'm surprised to not see more vapers using KGO. The fixed 3.7 voltage 1100 mAh is a great battery. Packs more of a punch. I also have the variable volt KGO. Sweet battery. Its only 600 mAh which is the only downside, but I keep a charger at work and one in my car for the cig lighter adapter. Variable from 3 - 6v. Check it out!