There is no best.
I'm over a year into this. Tried manual batteries and hated them, so I stuck with automatics. Tried cartos, but got tired of the funky taste after 3 fills or so. Tried clearos, but got tired of the leaking. Tried dripping and I loved it... Until I killed 2 batteries at work because I wasn't able to finish a full session. Tried the eRoll, and I love it. But it lacks the punch of my other batteries, even though everything else remains equal. I'm now about to order a bottom feeder, even though it's a manual, because it meets every one of my desires in a device. Hopefully I love this one enough to stop experimenting.
I guess my point is, until you figure out what you want and need out of a device then you won't find the "best". Just find what meets your needs.
Good luck.
I'm over a year into this. Tried manual batteries and hated them, so I stuck with automatics. Tried cartos, but got tired of the funky taste after 3 fills or so. Tried clearos, but got tired of the leaking. Tried dripping and I loved it... Until I killed 2 batteries at work because I wasn't able to finish a full session. Tried the eRoll, and I love it. But it lacks the punch of my other batteries, even though everything else remains equal. I'm now about to order a bottom feeder, even though it's a manual, because it meets every one of my desires in a device. Hopefully I love this one enough to stop experimenting.
I guess my point is, until you figure out what you want and need out of a device then you won't find the "best". Just find what meets your needs.
Good luck.