Manure separators are they worth it?

I was thinking about getting one, but from what I understand they don't put out extra slurry (from the separation process) and they put out reduced amounts of separated manure(obviously).

So other than using that manure for bedding what's the point? Realism?

I always have a surplus of straw from harvest so I don't think using the manure for bedding would be worth it and taking that separated manure to the biogas plant seems like it be better if I didn't separate it because id have more of it....