Like Jimbo the LS5/8 is one of my end game speakers, the Harbeth isn't on that list. But that's just me, and in my room I would expect the Harbeth to work better.

Either are fantastic speakers on the neutral side of BBC spectrum, and rarely available second hand so you'd be buying new? That being the case a home demo makes most sense, see how they work with your music and ears in your home. Neither needs insane amplification so a decent solid state integrated would give an adequate account of them.
Nice problem to have [emoji16], enjoy!


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