thoughts?

Ive used Zend & Rails in the past. Unless youre floating in cash scalability can be an issue in Rails and Zend is a bitch to get going. Anyone used the other 2?

I used CI for a while but hated its PHP4-ness. In the end I settled on Kohana, which was originally a port of CI to PHP5 but now stands on its own.

I like it because it's well-structured, fairly lightweight/quick, and provides useful tools without getting in my way when I want to do things the way I want to.

Rails actually isn't that bad, you just have to know how to treat it.

NGinx on the front end serving files and delegating requests, HAProxy for load balancing and then Apache/Passenger instances running rails. It's a fucking hawt setup and doesn't really take that much juice to run. Almost any Rails performance problem can be solved with memecached.

I've used codeigniter and, like stickman, switched to kohana. it's pretty decent if you are a php guy. if you don't have a preference i have to throw out a vote for django. it's lovely.