As it says, Schwalbe ain’t good value anymore.

Not tried black sharks but have ridden trailrakers which look to have a similar profile. I much prefer medusa / swampthing, mainly because I find them much more predictable on firmer trails. Whilst they aren’t as good as the more aggressive mud tyres in pure mud, they are just as good on wet roots, loose stuff etc, and much better on drier surfaces. It means I don’t find myself changing tyres as soon as it dries out, as I did with trailrakers.