Restrictions can get complex, not only being able to change without penalty, but it can be about refundability. If you cancel, with restricted tickets you do not get your money back, your ticket can be used for future travel. You have to be sure of what is important. Industry standard for changes seems to be a $100 penalty. If the fare difference between restricted and unrestricted is less than $100, and if there is a chance you will need to change or cancel, then you will want to purchase an unrestricted fare.
Oh how I long for the day when the skies were truly Friendly!