Airtangent vs Kuzma airline

Just bought the JC Verdier platine and want to get a tangent tracking arm.
I have received info and I am leaning towards the Kuzma or the swedish Airtangent .
The EM-2, Airtech MG-1 and the Condustor by the cartdridge man are also in the running but their build quality aren't in the same league from what I can tell in the pictures. How good are they I really don't know.
Opinions, or any comments wound be greatly appreciated.

Thanks