To RoR or not to RoR ,that is the question

I've been approached by a friend to engage on developing a web-application for electronic designers & students.I initially proposed CakePHP as my framework of choice.However my friend is an advocate of the Ruby-on-Rails framework.

The next stage would be ascertain which of the 2 frameworks would be best suit our objectives.
Both frameworks have similar features:

• Object-orientated
  
• MVC Architecture
• Open Source

The deciding factors will be:

• Learning curve of Ruby
• Availability of RoR servers
• Strength of the RoR community
  (compared to the PHP & Cake community)
  
• Special features of Ruby

Meanwhile , Im gonna research on RoR and the health of its IRC community.