Hmm, I had thought I posted an answer, but I suppose not.
The Moreplay isn't necessarily a good fit ahead of a solid state headphone amp, as the extra gain wouldn't be particularly helpful in any way that I could think of.
With a speaker amp (tube or solid state), then you would get some extra warmth and tubiness out of the Moreplay and the extra gain can be helpful as well if you need it.