Well, this is long ago ---
at that time the Chord replaced a Krell FPB300 in my system
with much much better results - it's extremely fast
and transparent. On the other hand it should be superior - at a much higher price point.
The switching power supply enables high output at low temertures and low power comsumption.
I had replaced the Chord with a Schnerzinger tuned tube amp, today I have a Schnerzinger tuned solid state amp. It's amazing what this company can do to your equipment.
The Chord proved to be a great starting point for Schnerzinger tuning, the result was amazing - unfortunately I could not afford to buy it back, as this tuning ist very sophisticated and very expensive, although well worth the investment.
I never heard the small Chord, but I'd expect the SPM 600 to sound fast and detailed.