I get the Studio Kat newsletter. She states that her patterns are not easy or beginner type patterns. She said when she began designing purses she decided to try and design bags that are like more high end designer styles. While I think her extra photos and explanation are bound to be helpful, I don't think her patterns are for the faint of heart.
On the flip side I have made several of Joan Hawley's Lazy Girl Design bags. They are very well written and easy to follow and always turn out great.
Just my humble opinion.