I used to use CodeIgniter almost exclusively till 2 years back, for developing small websites having mainly static text content and maybe a couple of forms. Nothing complex. But I switched to Symfony about 1 year into developing a slightly complex website, complete with user authentication & authorization, user profiles & management, an admin backend, …
Symfony does have a high learning curve, as opposed to CodeIgniter (which I was able to pick up in less than a weeks time). Not being an expert in PHP, it took me quite a while to get hold of how things are done in symfony; but I think it's well worth it.
You misspelled symfony in the poll options.