The only way to answer this is to try them both out!
We have and we now use ...........Vikan! we could easily supply salmon brushes but we are just not convinced having used them, they do make good floor brushes though.
I have another commercial make of brush in my workshop that I am very impressed with though. It offers mono-filament bristles, is slightly lighter than a vikan (not as light as a salmon) and it has a proper screw thread mount unlike the push fit salmon. We just don't know whether it is worth bringing yet another brush to market.
I now personally am using our new super-lite brushes on all my poles over 18ft as it reduces work strain, these are going out on Monday to our 10 Super-lite pole trialers, have to see what they think of them (they only weigh 239g, so lighter than a salmon)