I have been doing my pet projects in Drupal. I don't have much experience in the other options you mention, however. One thing I consider, is that side projec

I have been doing my pet projects in Drupal. I don't have much experience in the other options you mention, however. One thing I consider, is that side projects tend to die from lack of interest. If there is a person who might also work on it as a side project with you, using what they are willing to learn or already know might trump technical considerations.