Good to know the Luxman L-507uX is sounding great. I have the L-590AXII and have owned many integrateds and pre-powers, some costlier than the Luxman. As mentioned by others here, I share the same impressions about the Luxman. Without going into detail, I’ll just say it just sounds right and brings joy to the listening experience.
I’ve briefly tried the McIntosh MC275mkIV years ago and I’m not sure if it’s the typical McIntosh house sound. It’s warm with a full fat bass and lacks air, definition and detail. The overall clarity of the amp is not very good to me.