I have a few A2000 keyboards; one is mechanical and the devil to clean; the others use a carbonized rubber, but none use a membrane. I have 2 A4000 keyboards that are great.
For my PC I have a new 122 key Unicomp keyboard (they supplied IBM for a while, now make replacement keyboards for every old IBM model). I still have an old original IBM AT keyboard -- heavy, clicky, durable as a tank -- but it doesn't match my eyes! Er, I mean my black PC, so I replaced it.
I like the tactile and audible keyboards the best; the Amiga's are fav's with me because of the large return key; the PC-122 from Unicomp also has a large Return key.