Just by way of explanation, I see Jesus as a man who had to struggle. I believe he fought that fight from the wellspring of love within his heart for his Father, but I don't think it was automatic or easy. I believe his choosing was a free will offering out of the abundance of his heart. However, how could he sympathize with our weakness if he did not know weakness.
Heb 5:7-8 In the days of His flesh, He offered up both prayers and supplications with loud crying and tears to the One able to save Him from death, and He was heard because of His piety. Although He was a Son, He learned obedience from the things which He suffered.
Choosing is an implicit part of obeying. Choosing is not a negative, it is a positive, when the choice is positive. The idea that Jesus never had to choose makes no sense to me at all. It is like a stain glass picture in an ornate church. It is beautiful but not real. It does not translate into tears. Tears equal pain.
Father, it it be your will, make this cup pass from me, but nevertheless, not my will but yours be done.
The struggle of Jesus, his dependence upon the Father, being strength perfected in weakness, is the key to our liberation, in my opinion. The beautified image of Jesus as always flowing out serenity and never struggling with the flesh is to me, unrealistic and unscriptural and belies the true nature of his victory.
"O you of little faith, how long must I bear with you?"
He was a man. He was tempted in all ways like as we are, yet without sin. He struggled with the world, the flesh, the devil and he overcame them and in doing so became the author of our salvation. Throughout that process, he made many choices- always the right ones for the right reasons, because of the abundance of his love. The captain of our salvation was perfected through suffering so that he could lead many sons unto glory- who are to be perfected through the same process, "learning obedience through the things they suffer".