Spendor D7 vs. Harbeth Super HL5+

You need to go out and listen to the speakers yourself. This discussion will only make it more clear that loudspeaker choice is personal. I have listened to the D7 and similar Harbeths when I was searching for loudspeakers about couple of years ago. Both were good speakers. But based on my preference I would have gone with the Spendors. How does that help - except to confuse you more.

Some on the Naim forum liked the Kudos Titan 707 speakers more than the Spendor

I've auditioned the Kudos Titan 505 stand mount and 606 floor stander.They are lively sounding speakers.  But if I'm going lively, I prefer the Kudos sound to the Spendors.

I still listen to my first Spendor BC-1's  circa 1982. I also have Spendor S3/5As and S-9s. I'm a Spendor guy. Always have been. Having said that, I think Harbeth makes a more accurate and musical speaker these days. I haven't heard a D series Spendor that I thought was better or even the equal of the old Spencer Hughes days. If I was in the market for a new loudspeaker system, Harbeth would be my choice hands down. FWIW.
For reference, my system is all Audio Research tubes driven by a Koetsu on a Sondek table.

Remember, people, that Spendor still actually makes the Classic line of speakers, that derives from the BBC heritage. https://www.spendoraudio.com/classic-loudspeakers/

With Harbeth SHL5+, assuming room and setup are sorted, try any of the following amps ;
1. Naim NAC282 and NAP250DR or higher
2. Luxman L-509X or L-590AXII

3. LFD NCSE

All of the above will sound different with the Harbeth and the best sounding amps will depend on your listening taste or preference.