It's impossable to answer because with some you deal direct with the factory, with others an importer, some are made specifically for the UK 12fpe, others are FAC rifles with weak springs

And what is best? how can you compare a £1500 Daystate with a £150 SMK.

You could ask which manufacturer has made more classic must have rifles, than has made instantly forgetable pups?
I would think Theoben are hard to argue against.