As TRW, Sachs and Boge are all part of the ZF group, is there much difference in the levels of quality and reliability of their shock absorbers and coil springs, from 'brand' to 'brand'?

If so, which ones are of the highest quality, and which ones offer the best value?

Also, does anyone know which company manufactures springs and shocks for Ford in Europe?

In the US it's Motorcraft, but as Ford UK parts have 'Ford Mo Co' on them, it's probably not Motorcraft, as Motorcraft is clearly branded.