We are about to start a new Web2/AJAX app and are trying to decide if its worth the time and effort learning Ruby/RubyOnRails instead of PHP, CodeIgnitor and JQuery we currently use.
The key issues are clean/fast/modern AJAX UI, robust error handling, ans maintainability.
I would appreciate unbiased (if thats at all possible talking languages/frameworks) comments from experienced PHP and RUBY developers.
I can't say too much about Ruby, but I can say that I often feel like PHP gets a bad rap. PHP is what you make of it. Yes, there is a lot of awful PHP code out there, but you know, it was mostly written by people who would have written awful Ruby, or awful Python. PHP has such a wide audience that programmers of all stripes and abilities are using it, and many of them are writing bad programs.
That said, you can write good programs in PHP. Do you have good developers? If so, you can certainly write good code in PHP.
I think it's not about the language but the disciplines that are used in the community. If you are PHP developer who doesn't unit or functional test his code, nobody cares. There are bunch of PHP developers like that. If you are Rails developer and doesn't test your code automatically you're weird, something must be very wrong with you.
Ruby on Rails seems to me more than a framework, all the tools that come with the community. It is recommended that you use some kind of semiautomatic deployment tool like Capistrano. If you're not, you're weird again. And so on.
I agree with dicroce that you can shoot in your leg with both languages/frameworks. You could go with PHP and try to use some of the tools originally ment to Rails and i believe you get a great result.
The most important feature of a language is how much you enjoy using it. If you enjoy the language that you use, not only will your life be better, you will write better code and be more productive. Of course, this is completely subjective; however, I've never heard any first-class programmers talking about how much they love PHP.
Of course, getting to the level of fluency in a language / framework combination that you really know whether it is going to float your boat takes a big investment of time. In my opinion, the time that you spend will make you a better programmer even if in the end you decide that you like a different tool better, so, go for it!
PHP has a terrible reputation because it is so accessible. Anyone can start writing PHP, and most hosting solutions offer PHP these days, so there are a lot of non-programmer types writing programs in PHP. These programs lack proper computer science discipline.
There is a very widespread movement within the PHP community to move toward readable, well formed code as PHP starts to adopt modern language features. With PHP5, OOP became a practical reality and with that an explosion of books and material written about OOP best practices and development patterns. While PHP is often used to write malformed sloppy spaghetti code, the language facilities are there to allow developers to program in development paradigms like MVC, OOP, and TDD.
Not to mention, PEAR has greatly improved the quality and accessibility of community scripts. PHP's strongest asset is its community, and it has been becoming stronger and more disciplined. In many ways, PHP is very much like JavaScript--it had a very sloppy beginning from which the developers and community have been trying to recover. JavaScript is a very sloppy language, but there are some extremely powerful parts of that language that have brought it some well deserved respect in the age of Ajax and interactive web applications.
Languages like Ruby and Python are chock full of things geared toward computer programmers. If you hire a Python or a Ruby programmer, just by virtue of knowing the language that programmer is many, many times more likely to appreciate clean, well organized code than a PHP developer. That is part of the culture of those languages, and the people who evangelize them.
There is nothing inherently better about Ruby or Ruby on Rails in my opinion. Rails was the first mainstream MVC development framework, but its popularity and success has catalyzed the development of similar frameworks in every language imaginable. The choice to write Rails in Ruby isn't an indication that Ruby is better than PHP, which many could argue. Considering the time in which Rails was written and 37signals' fascination with obscure things, I can understand the move completely. At the time, web scripting languages were pretty lame, and 37signals was looking for a language that catered more to the needs of application programmers, not scripters.
You're not being held back using a PHP framework like Zend Framework, CakePHP, or symfony. CakePHP and symfony are both directly modelled after Rails, even if they aren't direct ports. Akelos is an actual port of Rails to PHP. Zend Framework is the most fully featured framework I've used so far. Don't be afraid to experiment, but jumping ship to a completely different platform isn't necessary and it won't change the way you do business. It's the same business in a different dialect.