Why is the Audio Research SP8 so highly regarded?

I had an old AR SP8 back in the day mated to a pair of Cary Audio slm 70 mono blocks driving a pair of custom speaker I built, man what glorious musical sound.

Later I had one of the first AR Ref 1 and it was better in everyday as I recall, transparency, soundstage you name it. Cant comment on the LS 26 but Im partial to the ref series pre. Never heard a cold lean sounding SP 8 or SP 10 pre. to me they where glorious tube sound for their time.

Times change.

Was it twenty-five years ago?  Was it thirty-five years ago when I heard an AR SP8 in a sound system at a long-gone L.A. stereo store?  Anyway, this was during my NAD 3020 days and I totally swooned when I heard the SP8 coupled with its companion power amp. Lean? Uh-uh. Cold? As a summer's day.  I dreamed about that damn thing for years but could never come close to affording it until the model was essentially a museum relic.

I found the original cold, sterile and perhaps lean.

Wow! Never heard this one before!!!! Nothing can be further from the truth! Sterile is 90% of today’s line and phono stages that can not even begin to give the listener any hint of the portrayal of space.

I had much experience with the SP8 with frequent listenings at a dealer. And I owned the SP-10 for 8 years in the 80s to early 90s. They both emphasized the middle 5-6 octaves which clearly brought on a most romantic, addictive, euphonic result. Sadly, this came with much compromise at the frequency extremes.

Both of these units were ALL about phono playback. They were a bit noisy so a constant update of the phono’s first stage tubes was imperative. The RAM ultra-low noise tubes back in the day were mandatory here.

Once the use of other sources such as CD players or tape playback came along, these units quickly showed their weakness to the units coming along in the mid 90s and beyond. And by then the ARC LS1, LS2, LS3 were absolutely horrible .... these were cold and sterile and dimensionally flat. Finally ARC brought the magic back with the LS5 and then continued on with the 25/26, Ref2, etc.  To use the SP8 or SP10 as either a line stage or phono stage today just makes no sense; far too much progress has been gained in the last 35 years.

I ran with the LS5/PH5 pair for another 8 years until I moved onto the BAT 31SE/P10, Aesthetic Callisto/Io, Aria WV5 and now Zanden for phono. This has been an ever increasing magic of 3D portrayal with tonal coherency, clarity and resolution gains at each step.

I did try the Ayre as a dealer demo, and this was way too dimensionally flat for my taste.

Just a little more context on my system. Currently running SP8 into an ARC VT100. My speakers are the JBL Classic 100 reissues. Sources are PS Audio Direct Stream DAC and PS audio transport. For analog I run the Dr Feickert Woodpecker with Soundsmith Zephyr cartridge and ARC PH7 phone stage.   

OP I bet that is a fantastic sounding system :-) a Ref 3 would be awesome IMO
( I am biased w a REF5se )