This is my situation too. I mean, I know PHP and I know CodeIgniter. I have tons of already ready to deploy code based in those idioms, so why port everything to laravel? or Ruby? Maybe down the line or something... but not when speed matters.
I spent the start of 2008 migrating an agency off CodeIgniter - it definitely improved their projects afterwards (developer training helped too, but not as much as a well-designed framework did for code reuse).
What gets me is CodeIgniter is how I was writing PHP code back in 2003-2004, 4 years after picking up the language as a hobby. And people still think writing it like that is a good idea.