Is Django more practical for a social web app or Rails? Getting back into web programming... >> more in description

Is Django more practical for a social web app or Rails? Getting back into
web programming... >> more in description

Apologies if this is too discussion-based, just looking for some
experienced direction.
I went through Michael Hartl's entire tutorial >>
http://ruby.railstutorial.org/ and completed the 'Twitter app' exactly one
year ago. Since then I haven't had the chance to get back into
web-programming (I took Java as en elective my last year in college). I
now have free time again to invest into web-programming, as it's something
I've always had a passion for (just never the time).
I have a mockup of a social-web-app I'd like to work on and asked one of
the web programmers at my job if he thinks I should go back and try
re-learning everything in Rails - or start fresh with python and jump into
Django. He pretty much said it doesn't matter - learning python/django
will feel more 'streamlined' but I might not understand what's actually
going on - while Django might take longer but I'll have a stronger
understanding. I remember understanding the basics of Rails and OOP, the
MVC structure - but I agree that 'gems' would just do things for me and I
understood what they were doing, but not really why.
So, for a social network type of site, which language and framework do you
think is a better choice? I'm open to other options - just looking for a
concrete answer, or some type of confirmation that it doesn't 'really'
matter...
(sorry again, next time my question will be a specific programming
problem, hopefully about some dilemma Rails or Django haha)