Correct me if I'm wrong, but in French I believe it is also meilleur for both, but for emphasis you must add plus.
???
Sorry, you can't use "plus" with "meilleur" as "meilleur" is already the word for "plus bon" (literaly more good)
You can say : "plus efficace que ", "plus performant que ", "plus fiable que ", "meilleur que" but
not "plus meilleur que"
If you want to ask for the best, you can say : "le plus efficace", "le plus performant", "le plus fiable" or "le meilleur"
Anyway, if your 12V signal is quite good and/or your application does not need to be very reliable, use resistors.
If you require galvanic isolation and/or common mode noise rejection, an optocoupler is the way to go.