Owning an iPad 4 and an iPad Mini?

I'm currently the proud owner of the iPhone 5 32GB and an iPad 4th Gen 16gb WiFi. I'm considering purchasing a Mini to use on my commute on the bus and for my lunch breaks. I've taken the iPad 4 into the city a few times and I get annoyed at lugging it around. I switch it between arms constantly while walking and I just find it a little too cumbersome, but man is that screen pretty. When I'm home, I use it for YouTube, Netflix, HBOgo, web browsing and such. I'm wondering if I should get a Mini to use on my commute and lunch break for my e-book consumption and social purposes. Is the lightweight formfactor really worth me getting a second iPad? Should I just get rid of the 4 and go with one Mini? Does anybody think it is ridiculous to have an iPhone 5, iPad Mini, and iPad 4?