There are 3 separate issues involved -
1) - How does the BLADE cut ? Ie.- dynamics of the blade design / grind etc.
2) How does the KNIFE lock up (or not)? Ie.- slipjoint, liner / integral lock, lockback etc. Hey, how about a fixed blade ?
3) How do YOU DEPLOY THE blade ? Ie.- nail nick = 2 hands, thumbstud, assisted, auto = onehanded ??
I think one will / must find the best combination of those factors to suit one's needs. Not to mention availability. Legality perhaps comes a distant "other" consideration.
All things being equal - ie.- the blade cuts well, I'd rather have a knife that locks in the open position, not in the closed position, no closing bias (ie.- like lockbacks and slipjoints) and can be opened (and closed) one-handed. Whats legal in my area are liner locks and integral locks. Thats what I use and have quite a number of.
But in a SERIOUS situation, nothing beats a good tough fixed blade.
Its the whole package, and whether or not you can lay your hands on it, when it counts, that really counts.
Just a few thoughts. Cheers. Jason.