This is about the use of personas, primarily in the agile development realm.
What value, if any, do personas give during implementation?
On agile modeling, the discussion about personas remains in the context of requirements investigation.
On wikipedia, the benefits are described to "assist with brainstorming, use case specification, and features definition."
I'm familiar with personas in use while writing user stories such as the following:
As Willow, I want ordering a combo meal to give me the option to select alternate sides.
As Xander, I want the default side to be selected when I order a combo meal.
In these examples, Willow is the nutrition-conscientious user of meal-ordering software and Xander is the hungry, impatient user that thinks "fast food should be fast."
When coming up with these requirements, it may have been helpful to have the personas in mind. I imagine a possible discussion:
Person 1: Willow needs to have more options than fries for the combo meal, otherwise she would never order a combo.
Person 2: But Xander doesn't want to have to sift through different options when ordering a combo! He just wants fries and he'll probably always want fries.
This discussion may have created the two requirements above, but once the requirements have been created, why do we mark each requirement with a persona? I wouldn't code the 'default side' requirement any differently knowing that it is for Xander. What value does retaining the "As Willow" and "As Xander" starts to the requirements once they have been written? What value does the persona give to the one who implements the requirement?