I'll try to describe my experiences with the Opinels compared to my Buck lock backs.
I think a locking folder can "fail" in 4 ways.
- The lock can fail unexpectedly. This mostly happens when you pry or stab with the knife and create a strong closing force. As a rule, I don't do this with folders so it's not something I worry about. Note, I've heard of Buck 110s closing while under very hard cutting in what might be called a sling shot type failure. And an Opinel's lock ring can move while you use it, allowing the blade to close unexpectedly. I just keep my thumb and eye on the lock ring to monitor it. Also note, the Opinel lock ring is very, very, very weak, especially compared to the Buck's lock back but again, I try to not rely on locks.
- The knife can develop vertical play (aka lock rock) after repeated hard cutting. This is what has killed every plastic Buck I've owned and I have other lock backs that have worn out in this way. I don't trust lock backs with lock rock as this is what leads to sling shot failures. The design of the Opinel's inner collar makes Opinels more durable to this sort of wear. After a lot of use, it is possible to simply wear a divot in the inner ring and blade and for the blade to "rise" more when opened. But they don't develop lock rock.
- A knife can develop horizontal wobble at the pivot, especially if you pry with it. Buck 110s aren't strong at all in this regard. Opinels are amazingly strong in this regard. You'll break the Opinel's blade long before it developed lateral play.
- The blade pivot and lock mechanism can become fouled with dirt or debris and not lock correctly. This doesn't affect the Opinel's lock at all but it does affect any lock back, including the 110. I'll be working outside this weekend in a sandy environment and will take an Opinel, not a Buck for this reason.
The Opinels are quirky and require some knowledge to tune and maintain. Other members here are very helpful and directed me towards Johnson's Paste Wax melted into the joint to help prevent them from seizing up when wet. But even then, they're fiddly. And in the end, they aren't a Buck 110.
But they are very durable and very light. They're incredibly capable knives.