I also started using CodeIgniter and i also had, at some point , the feeling that it "just doesn't feel right". If you want to learn a new language i'd probably go with RoR otherwise take your existing PHP skills and use Symfony 2 (http://symfony.com/). It definitly has a steeper learning curve than CodeIgniter but i couldn't think of a single point why i would prefer CodeIgniter over Symfony 2 now.