I thought Modern PHP by Josh Lockhart, also the author of PHP the Right Way, was a helpful overview.

http://shop.oreilly.com/product/0636920033868.do

It's come on leaps and bounds in the past few versions IMO. Partly because of new language features (proper namespaces (enabling easy autoloading), traits etc) and partly because of the community pushing decent standards [0], [1].

It's also worth pointing out that since 5.3 the Laravel framework [2] has been created and in its latest iteration it draws a lot of inspiration from ASP.NET MVC and Rails (the former resonates with me coming from .NET land; though I've not much experience with the latter), making it a great framework for rapid prototyping. Its coding style encourages a lot of good practices and it's become very much the go-to PHP MVC framework, at least for me.

A good resource for reading up on 'modern' PHP is PHP the "Right" Way [3] - there's also a (very recently released) O'Reilly book on Modern PHP [4] written by the creator of a popular micro framework [5] - I've not had chance to read it yet (and I'm sure I'm not its target audience) but I have enough faith in the author to know it'll be a worthwhile resource.

Having said all of this, it is still PHP and you will still be working with some of the old quirks. I've just grown somewhat fond of them :)

  [0]: http://www.php-fig.org/   [1]: https://getcomposer.org/   [2]: http://laravel.com/   [3]: http://www.phptherightway.com/   [4]: http://shop.oreilly.com/product/0636920033868.do   [5]: http://www.slimframework.com/