As my 2008 MacBook Air is on its last legs I'm starting to look around at upgrade options. I am considering letting my iPad do all the mobile computing stuff I need and getting a dedicated desktop system - either a Mac Mini or 27" iMac (I'm open to hearing suggestions about the 13" rMBP as well). Just looking for people's opinions on the pros and cons of both systems. I previously owned an iMac when I was in school and loved it, but now I'm thinking that the Mac Mini affords more diversity than an all in one system such as the iMac (and it's cheaper). Opinions, Go!