Mark
I have Vallejo model metallics, Vallejo model air metallics, Vallejo game air metallics, Vallejo liquid gold metallics, printers ink, Darkstar metallics...
All the 'silvers' are pretty much the same within those paints : finely ground
The alcohol based liquid golds are a pain to use
The printers inks dry in the pot and need to be protected with a varnish layer since they re real metal flakes
For the gold ones, the Vallejo game air and Darkstar ones are very good while the vallejo model metallics are also not that bad.
But you know what, I am now experimenting with making my own paints using finely ground mica and real metal flakes : I buy it from a well known local manufacturer of artist paints
In my humble opinion it is the way to go since you can make them on demand and get any shade you want. It is actually really easy to do.
Cheers
Alex