Yes, there are apparently some different scenarios (perhaps DRM? I forget) where the non-free codecs in Packman are better. I would install them, just be aware when you do zypper dup that Packman will often lag behind other repos in the version number and you should choose the option "keep obsolete" when resolving the conflict, otherwise you'll end up with a mix of codecs from the openSUSE repos and from Packman.

https://en.opensuse.org/SDB:Installing_codecs_from_Packman_repositories