Some people have tried zenith for a couple of weeks now. If you are looking for a Subtank minis upgrade that is not occasionally leaking and also has the prebuilt coils then you can consider innokin.
Pros:
This never leaks. Neither tank is leaking the drops of juice and the other which are not ben treated gently.
The usual which you have heard before and it is also easy to fill and change the coils. There are also decent flavors for the break in the period, options for good airflows, and long-lasting coils.
Flushing on most of the devices but there is also a gap. But MVP4 is mostly known for this.
Cons
1.6 will take a while for breaking in. This also means that you are vaping around 4ml of juice before getting the full flavor.
After the break in the period, the first thing in the morning is that you will get the rubbery taste for 30 minutes and then the flavor would come back.
The flavor is getting better when you are using all 4 air holes. There are a total of 5 on it, but it is not able to pull the juice from all the 5 which are open. There is also loose vapor when 4 are working better and 3 also work but in 4 you will get much better flavors.
When the tank will leave the house then you want to fill the capacity. Some time it is very hard to find out because there is a black piece of the metal blocks that are viewed from the juice level when it is filled high enough.
People are also not crazy about the drip tips. When you will try the .8 and .5 coil then it is very short. You have to change the sub ohm coil when it is at high watts.
The coil which is coming with the tank is still going very strong after the use of two weeks also. If you want to stop this weird taste then you can stop another coil. You can pull out the cotton from the coils and as the cotton is burnt from places.