I've built a few digital asset management apps for fortune 500 companies, CRUD apps for non-profits, and several different startup ideas (sites, mobile, etc).

I've built a few digital asset management apps for fortune 500 companies, CRUD apps for non-profits, and several different startup ideas (sites, mobile, etc). Nothing I've made has required a lot of input form complexity, which seems to be Symfony's strong suit. I think you might be right about the project sweet-spots. Symfony certainly seems equipped to handle workloads you describe -- I've not seen form input validation as complex as Symfony.