I always use the 1976 curve because it reduces the amplification of sub-sonic cartridge garbage.
I was just leaving the industry in 1976 and it was introduced to deal with one of the many faults of record players ie the amplification of the erroneous signal they produce below about 2xFn which is unavoidable in seismic vibration transducers.
The "audiophile" LP lovers tend to slag it off for the same reason, perhaps, that they love LPs in the first place...
On the Devialet the subsonic filter probably does the same thing.