Cartos are funny things sometimes... but there is no better way to use them than a bottom feeder.
When you first fill a carto, it has to overcome the added resistance of being full of juice so performance suffers for a little while until you vape it down a little. Then it hits the "sweet spot" of having just the right amount of juice to vape really well... until it starts to get empty and you get below the perfect amount of juice.
Using them on a bottom feeder allows you to keep them right in the sweet spot all day. After you vape them down a little and get to where they are just right, you can keep them there by squeezing the bottle every now and then. It might be a bit of a learning curve, but you'll figure it out fast.
I use the boge 2.0 ohm carto on my bottom feeder pretty much every day. Sometimes, I use a 2.0 ohm cisco atty on it (which is also really nice), but the more I use the boge cartos on the juice box, the more I like it. It's about as hassle free as anything I have can be.