Disagree about any benefits of take-20. The mechanic turns everything into a binary yes-no exercise, where in reality there's no way of knowing whether your failure is caused by your having an off day (or consistently missing something) or by the task being flat-out beyond you.I think this is exactly backwards. The value of a Take 10/Take 20 mechanic is that they show precisely what is possible with absolute certainty, and ideally should have the requirements (and/or consequences) of using them laid out ahead of time. Take 20 tells you exactly what the "range of locks" a character can pick is, and provides a mechanical model for the situations in which you don't "need to ask for a roll."
Take 20 mechanically isn't an addition to 'don't roll if it doesn't matter', it replaces that model wholesale, by making it clear exactly what the capabilities of the character are, when they aren't under pressure. It's frankly a quite elegant mechanic that it's a quite a shame has been so deprecated in modern designs.