The longest you have owned any gear?

Both Rega Kyte and RS1 loudspeakers for over a decade each. And these were days when 2 or 3 years were a long time in audio.

The Kytes were vivid and RS1s a little more muted but smoother. Within their bandwidth they were at least as good as anything else I'd heard.

My Marantz CD 6000ki is getting on for 15 years and I can't imagine why I would get rid of it whilst we both keep working.

For me it's a question of satisfaction. That usually happens when things sound balanced and correct in the midrange. Its when you start looking for resolution in the extremes, especially sub 35Hz bass that things can get tricky.

I purchased a Sansui QRX-6500 "Quad" receiver for $512.00 in 1973.  Was my main receiver until 1987.  After that it was my garage sound system receiver until 1997.  24 years....a beast of a receiver and beautiful too!!

PS Audio Lambda cd transport purchased new in 1993. Wonderfully musical. Great rhythm. Legendary.
I preferred it to my CEC that I purchased some years later and sold. https://www.stereophile.com/content/ps-audio-lambda-cd-transporthttp://

A luxman t110 tuner that I bought new in 1977. Since I no longer listen to fm radio at home, I sold it last week.

My Pioneer SX980 receiver from ~1979. It is still used in the laundry room.