I have stock mounts, and they are fine... I may do something different in the future...
denis and jay have... I think mounts from an E28...?
my engine builder recommended E21 'california' motor mounts... they are like, blue or something and very durable, but not uncomfortable.
maybe an E21 owner among us has some insight...?
also, someone here (d clay?) filled his stock mounts with urethane...