Decca's were their own worst enemies! You are not alone in giving up on them, almost all of us moving to LOMC's in the mid-70's. The guy who was making them for Decca bought the rights to the cartridge when they decided to get out of the game, and went to work on redesigning it. The Super Gold Mk.7 (with a line contact stylus, opposed to the Van den Hul profile of the SG Mk.6 stylus) is the first Decca/London with the cartridge's weaknesses eliminated (or at least reduced) sufficiently to make living with it not a love/hate relationship. The improved mounting option, the Deccapod, helps a lot, and there are now four wire tags, not the old 3-wire design. The London Reference is very different than the old Decca's, even having a machined body housing!
My old pal and dealer Brooks Berdan loved the Lyra cartridges, and his son Brian now sells them at his shop (Audio Elements) in Pasadena. I'll have to take a listen to the Etna.