I’ve used the wooden and wire, and they do work. Setting the small ones I always get a little nervous about my fingers. I saw the rat size ones in the store and yikes..
I tried the easier to set plastic ones. They're easier to set because the spring is much weaker. The mice have lighting reflexes, and would pull away before the trap could close. Either that, or the spring wasn't strong enough to crush them, and they'd pull out and run away.
Whenever I'd check them, they had tripped, the bait was licked off clean, and there wasn't a mouse hair left.
I don't recall ever having the metal ones trip and not catch the mouse. Once all it caught was some long grey hairs, and I tot quap, dat's a wat. Got da bigger an' badder wat twap version, an' caught da wascally wat.
For someone who really can't functionally set a wooden trap, the difference isn't of degree but is a 1-or-0 situation. There are different manufacturers, the Time's Up or Snap-E have performed well:
The one weakness I've discovered (recently, as it happens) is that if the target is trapped in such a way that it survives and has freedom of movement to gnaw at the trap, it will chew the plastic shell off the bar, and other exposed plastic parts (much of the trip-lever in the case I have in mind).
I present my experience as an option. The wood-and-wire traps are less expensive and quite effective as well IME. They're harder to set, however.
I've seen bait thefts with both versions. One learns to be creative in how and where the bait is applied, and sets multiple traps for redundency. The trapper only has to be lucky once, the mouse, every time.
