I use them on occasion like everybody else, but the terms "soft" and "hard" are extremely misleading as descriptors for the hit of pool cues. Aside from them being subjective things that we all experience very differently, those terms are also commonly used by people to describe two completely different things, and the person using them almost never specifies which of those two things that they are talking about or if they are talking about both.
"Soft" and "hard" are very commonly used to describe how much/what type of vibration/hand shock they feel with their hands, but probably more with their stroking hand, and they are also very commonly used to describe how much shaft flex they can feel with their hands, but probably more with their bridge hand. Those are two very, very different things though that don't necessarily have to be related.
For anyone hoping to get half helpful cue brand suggestions from others it is always best to be very specific about what amount/type of hand shock you are looking for, AND what amount of shaft flex you are looking for, otherwise people are mostly just blind guessing about what you actually mean when you say "soft" or "hard" because people use those words for different things.
On a side note, for wood shafts, the only thing that really affects the amount of shaft flex is the shaft taper, shaft diameter, and the type of shaft wood, probably usually in about that order. For the felt hand shock, that is affected by the shaft material, the tip, the shaft taper, the shaft diameter, the ferrule, and the materials used in various other cue components, probably roughly in about that order most of the time.