I don't know about the Lum Chinese but the Rainbow Leek has a very strong lock.
It's a frame-lock (like the Sebenza and the Mnandi) instead of a liner-lock and I can't imagine how you could get it to fail.
As for how grippy it is...
While it is all steel, it is very secure in the hand.
The reason is because the handle is so slim and flat you can really get your hand around it (but it's long enough for all of your fingers), and when the blade is open, the flipper creates a guard to prevent your hand from sliding on to the blade.
You owe it to yourself to handle one.
Good luck,
Allen.