For a MTL and restrictive DTL tank, easy to build, takes lots of different types of coils, decent juice control and top fill, I reckon the Kayfun v5 is really hard to beat. The only downside is its size. It's a big boy.
Svoemesto will be announcing the TPD compliant mini v5 soon so that should reduce its size whilst retaining all the good points as above.
For me, the v5 is pretty much perfect.
I'd be interested to see what others think however.