oneEqEddy has the same principle as Smagorinsky, but the advantage will be in the transport equation of k, which gets rid of the assumption of Smagorinsky model saying "balance between the SGS energy production and dissipation". I would say this is true only if the eddies are "small enough". So oneEqEddy "is less wrong" than Smagorinsky for coarser meshes. Moreover, the locDynOneEqEddy is implemented, where the coefficients are locals, and not global. However I saw people complaining about negative values of nu_sgs using locDynOneEqEddy, and some people claim it's the backscatter, some say it's unphysical and should be limited to 0.