It's always a good idea to use base technologies that have already been proven to work well together. Although using the latest trendy language or framework might be all the rage, stacks that have been proven to work at large scales are going to save you time and effort.
Being on the bleeding edge for every element of your application can soon become tiring. You don't want to get yourself into the position of having to wonder if the web server is at fault every time you hit a bug.
Cal Henderson - Building Scalable Web Sites