I have some regrets selling...

Yes, but learned from it as well. (Mac-ss amp, Supratek, Jas _both preamps.) Thought about selling my ML Aerius i but I can not get over the years of pleasure those stats gave me.
Besides......I still love the way they sound.

Threshold Stasis 7.0 Amp: A Power House from what I recall listening.

In some ways, I regret dumping a mass market system I had many years ago. If I had it today, I could listen to it from time to time, to remind me that whatever problems my present system has, things could be far worse.

Ohm F speakers. I needed the money to go to Grad School and got what I paid for them and they were three years old at the time I sold them. They were a great speaker and I have wondered how they would sound with the front end and room I have today. Oh well!

Miss my precision fidelity C7 preamp..cannot remember how I disposed of that; college days.

Almost everything I've sold I miss.
Especially my old Dynaco ST-70 and my Pass Aleph-3

My uncle gave me his old Fisher 400 tube receiver (circa 1963) - real wood case, warm lovely sound, great tuner - in mid-1970's and I traded it in around 1980 for a really great (at the time) high end system.

10 years later I sought out a Fisher 400 and found one in good shape, had the "Fisher Doctor" renovate it. Very happy with my "retro" office system (Thiel 04a, AR ES-1)

Art