I have a late 2012 top-spec iMac - 12Gb RAM and i7 CPU.
I added a new HD to it - Seagate hybrid 1Tb - when the original starting showing signs of a potential failure.
Works fine - usual signs of usage from a device this age, but going strong!
Looking to downsize to a Mac Mini - with a 4 core CPU and similar specs to the iMac...
Anyone interested?