I remember, yes.
I never owned one, no. And I’ve owned only Macs since 2003.
Plus an eMate in 1998. Wasn’t with a socketed chip.
Not really sure why it would improve anything. Changing the chip usually meant sticking with the old, slow bus. Which meant the RAM was slow, too.
I did upgrade to more RAM and SSD every chance I got, though. Apple’s RAM upgrade surcharges are ridiculous. Ditto storage.