Both as very high in musicality.
LFDs seem to work well with English speakers that love the mid ranges, like your Spendors. Very clean sound with nice soundstaging. Vocals integrate well.
McIntosh will power through any music with real slam, and unlike most recent McIntosh amp designs, the 6300 does not seem to be overly "tubey" or "warm" on the high end. They seem to work with a wide variety of speakers, especially smooth sounding ones, top to bottom.
From an investment standpoint, LFD is a cult brand with a limited audience. The company is little known in their native UK and does not even have a website. It operates like a small cottage industry.
McIntosh is a luxury brand with huge built-in loyalty and will retain its value. My father had a 275 MAC amp in a custom JBL console. He died in 2004 and we had 45 bids on eBay for it. It surprised me and my brothers on just how strong their base is.
