I have an iPad 2. I use it all the time at home. I read on it, play a game or two and watch the occasional video. With these tasks, if the iPad is available, I prefer it. I also have been blessed with an iPad 4 LTE from work. I use it on the road for presentations and entering data to the company's CRM. I have an iPhone. Love it too. But I can't picture my day without my iPad. The larger screen is useful. It's also my preferred email device.
I use my iPhone much more. I pretty much only use an iPad for watching movies on airplanes, reading eBooks and as an Air Video middleman for streaming non-itunes friendly video content from my Mac to my Apple TV. I sold my original mini last month and going without it has been a piece of cake. I would have been in full withdrawal after 48 hours if that were my iPhone.