i am legendary. i use it 100% of the time of 50% of the time.
kidding aside, it is just one tool and you should use it if you need it, if you don't need it don't bother with it, it's not an oversimplicfication, it is as simple as that.
you mention issues with timing, use it, if you're timing improves, great you used the right tool correctly, if not, perhaps you used the right tool incorrectly , the wrong tool correctly, and /or both.
its like asking abut using music, well if you dn't know the music, i.e it isn't memorized then you'd prolly want the score out in front of you, if you have all of it nailed down all notes, all dynamics, composer remarks internalized 100% of the time you can get by with practicing without a score more than not i suppose.