Although plenty of people argue with me, LR cartos and Attys drastically shorten the life of ego batteries. Your welcome to do a study if you would like, I did. But regardless, using protected lithium ion batteries with low resistance causes 0 problems! In that regard it is awesome! Plus replacing the 14650 battery is around 5 bucks, versus the 20 you will pay for an ego battery. Lithium batteries have far better life then mosfet driven batteries, and they are so cheap you can have plenty of spares. I cannot find a con anywhere on this product. I use a roughstack so I wont be buying one, but I could see it as a backup for sure! I doubt you will see any bad reviews on this item. BTW, Madvapes rocks! They love giving free stuff out, and if they mess the order up, you keep the mess up and they sent the right stuff, plus fast shipping and fair prices. They are a great company.