Smiths 18 Jewel or 19 Jewel mechanical, is one better?

I recently purchased a Smiths Automatic, and have fallen in love with it. It’s marvellous – but now I’ve got the Smiths bug. I’m torn between an 18 jewel, JW Benson (smiths produced) and a 19 jewel smiths.

anyone out there with the technical know-how to shine a light on these movements? Is there a better one, technically speaking? What should I be looking for? Any thoughts would be greatly appreciated.

this is purely for a personal enjoyment, I’m not interested in…

Smiths 18 Jewel or 19 Jewel mechanical, is one better?