Spring toggles won in this test...
But I personally don't like how much play there is when you attach things, for example you need a 14mm hole for the M5 version, so there's 9mm of play! Also, they fall down inside the wall if you undo them for decorating, etc.
I'd go for
toggler in your case, came second for strength. They still need a fairly large hole, but it remains centred when you slide the little plastic bit into the wall.