A lot of people love these Luxman integrateds, and I think they're impressive when it comes to detail and delivering that "live, in the room" sound. They look cool, too. But like most Class A amps, to my ears they're rather bright and fatiguing, even the 590 and 509 models. I auditioned the 550 last week over Harbeths, and even those extremely warm speakers couldn't tame its upper end. I know the salesman agreed with me, and we both preferred an LFD integrated in the same room, but I've spoken to others who think the Luxman is clearly superior to LFD, so YMMV. Anyway, to answer your question properly would require more info on your setup, but the best speakers I ever heard the 550 paired with were the Gershman Avant Gardes. Again, that's a warmish speaker, and in my opinion these Luxmans really need that. I'd look into Spendor, JM Reynauds, Harbeth, although if you can handle that high end, they were very impressive with Devores.
