Classical VS Double-density.

I have been experimenting with SPH recently and presently have a bake going. However the decision of classical or double density confuses me.

In 0 gravity , classical explodes into the expanse in clumped blobs (not a desired affect) Whereas double density sort of grows as a single blob around the emitter (also not what i expected)

I also took note that the classical solver was greatly slower than the double density version; although i have no benchmarks to back it up.

Does anyone else have something they would like to state that might help me?


I would also like to know what this is. The Wiki hasn’t been updated to explain it and I can’t find any other discussion about it…