The whole spontaneous vs. recited prayers argument is not really an "either/ or' argument. It seems to me that if you recite the psalms until they are memorized, then they eventually become part of your spontaneous prayer: Those phrases phrases spring to your lips when you are away from the prayerbook. The net effect is that your personal prayer language becomes lovelier. Instead of "Lord, please help me keep my big mouth shut so I will stay out of trouble", becomes:
Set, O Lord, a guard over my mouth;
keep a watch at the door of my lips.(psalm 141)
In other words, using formal prayers will inform or expand your spontaneous prayer life. Don't you agree?