Best indication of how a knife will shave your face, without actually shaving your face first, is how well it will take hair off your arm.
While the Swiss army knives I've encountered could remove hair from my arms, not nearly as cleanly and efficiently as my Buck.
After testing on my arm and being wowed, I have indeed shaved my face and neck with my Buck 110 Paperstone Ecolite.
My Byrd Rescue 2 took hair off my arm just as well as my Buck, but I didn't trust the serrations against my skin without creating pizza