After 10 years of PHP development, I got a chance to develop something with codeignitor. I fount it awesome experience, the simplest framework ever developed. I had to revamp a legacy application developed long back in php 4 and the application had a good user base. I had to stick with the working database schema and reuse the same, because migrating schema was almost impossible at this stage. Codeignitor fits my requirement and I found it best PHP framework I ever worked with.
Thanks to all contributors!