Found an interesting framework for rapid application development- CodeIgniters. I actually feel good now for shifting from Symfony and am confident have saved lot of efforts and time.

Here is the comparison of the two frameworks:
1. Symfony is interesting to work with. But the difference in two versions is a big pain. If you are searching for symfony tutorials and find any solution, then just make it sure for what version the tutorial is. I suffered a lot because of the difference in two versions. So, my view: symfony tutorials’ online presence is not that assuring.

2. CodeIgniter is whole lot flexible than symfony and you can do what you want. So, the actual fun with CI is you know whats happening inside. Though symfony ease up your efforts but the efforts in learning how to ease up efforts for future can be frustrating.

3. If you seriously are aiming for rapid application development for some idea and are committed to sit back and code things you want, instead of altering user stories which ease up things due to framework dependencies,  I strongly suggest CI. My view is CI has the power to replicate all your ideas to code in action.

4. Symfony has a big learning curve and eventually you end up doing same things taking more time as compared to in CI.

CI does not has internal support for AJAX, but due to its flexibility and openness, things are very easy to integrate. Will come along with the best practice to use AJAX along with CI very soon.