I think they certainly fall in the same category, but I'm hoping that the iPad Mini will be slightly better in some scenarios where my Nexus 7 fell short.

I sold my Nexus and have preordered an iPad Mini to see if it'll be more usable while still retaining the portability of the Nexus (which I loved - you could actually stick it in your jeans back pocket)

Browsing the web was fundamentally frustrating for me on the Nexus 7 because you'd either be served a mobile site which looked awful because it was meant for a 4 inch screen or you'd be served a desktop site where you had to do a lot of pinching and scrolling to get the text to a readable state which felt like more work than it was worth.

Especially in horizontal mode the Nexus 7 felt like browsing the web through a letterbox because the OS is quite greedy with the screen real estate and the 16:10 doesn't have that many pixels to begin with.