Several years ago, I enjoyed a brief flirtation with MAM knives, and carried the locking sheepsfoot for a while. I have also tried Antonini, and a couple of Jokers with Opinel-ish locking collars. None of them has dislodged Opinel from my pocket. The main reason is carbon steel, which seems to be available on only the beechwood Opinels, and on none of the other brands.
MAM, along with Antonini and Joker, do get one thing right. Their handles are flattened on the sides so they ride more comfortably in e rthe pocket. I have used Opinels for 45 years, but never liked them in my pocket because of the big lump they made, especially the flared pommel, but also the round barrel handles. It never occurred to me to modify the handles until I got here and saw how easy it is.
The Virobloc is not at all annoying to me. It is simple and elegant, and works about as well as it has to. If it is too tight, you can open up the ring with an appropriate tool. (I don’t know if you can use the snap-ring pliers you used to get it off, but if not, you’ll find something.) if it is too loose, a pair of channel locks or Knipex pliers will work or maybe you can just shut a drawer on it.