When I began to think about the topic of working from photos or working from life, I thought back to when I first began painting. At that time I was focused on recording all the details I could. I had very little thought of how my paintings could be more than just a faithful recording in paint of what the camera had captured. Photography became a crutch for me. In the end I slowly lost the skills of drawing and the sensitivity of color, value and edge information needed to help communicate my own unique vision of the world around me. Sure my paintings looked like the photo I was working from, and on occasion, I was able to capture a little bit of the life of the subject I was painting, but for the most part my paintings were lifeless. I was lacking all of the things that make for an interesting painting and for me, probably the biggest, poetry. I know poetry in a painting is pretty vague and very individual, but I think we all feel it when we see it in a great piece of art.
Painting from life has always been about the experience and the knowledge gained from studying life. I cannot think of any better way to grow as an artist than to work from life. A question to ask yourself is what is more.