I'll buck the trend. I own a '4' and a mini...we also have a pair of 3s, specifically for our business. My wife's daily driver is the iPad 2--we've handed the original iPad down to our son. I like having both the big iPad and the mini--I honestly DO use both and for completely different situations. The iPad 4 is my morning newspaper with Early Edition and it goes with me to the studio in the morning. The mini is excellent for reading in bed, lounging, or on road trips to our cabin. The ONLY reason I bought the 'mini' was because I had shoulder surgery. Rotator cuff, SLAP repair (labrum) and a SAD (sub-acromial decompression). Pretty extensive surgery and it made it impossible to hold the 'big' iPad those first couple weeks (surgery was almost six weeks ago)
I love the mini. I bought it at Best Buy as I've got sixty days to return it. That was my plan all along as I bought it on launch day so I've got til the beginning of the year to return. It's not going back. Ever! I'm using them both constantly.
We may represent a different and niche situation as we run a mobile audio and video production business. We are out doing 125 events over the course of the year. The iPad has transformed our business. From client contracts to music for wedding ceremonies. Redundancy for live shows and a backup to the main rig, slide shows and recording bands. We are also getting ready to buy into Mackie's new love mixing rig. So we aren't just buying iPads to have them around the house. We do use them a lot.
I do see different purposes for the mini vs the larger iPad, especially with the A6 update. Much easier and quicker to edit on both GarageBand and iMovie...fast app switching and no delay in our primary music playback program dJay when loading tracks from the library to the decks. The power in the iPad 4 is amazing in comparison to the '3's we have. Just seems effortless in all tasks. I'm considering sell the pair of 3s and grab another couple of the 4s as the Mackie rig will allow mixing on up to 8 iPads simultaneously. 8 tracks per iPad and another to mix live from anywhere in the venue. It's an incredible way to set up sound.
Business aside, I can see the allure of having both. Even in 'just' an individual or family situation. The mini is much more of a media consumption device for me. Surfing, email, casual gaming, media, and FB. Easy to carry, able to run every current app, convenient, light weight, discrete, et al. The iPad 4, IMHO is starting to really come into it's own (for us and our situation) as a 'creation' device. It's just as powerful as laptops only a couple years old...but with much faster data access and an incredible amount of awesome software.
Sorry. Didn't mean to go on like that. But if you're a budding photographer, dabbling in video, enjoy painting or drawing...even coding, writing a book, checking wifi networks, the list goes on...but in these situations I can very much see the justification of owning each.
I didn't know I needed the iPad. Never dreamt of such a device pre 2010. However, since owning the first one I've made it a cornerstone in my life. As well, the integration with the iPad, iPhone and our Macs is unreal. iCloud works great for what we are doing!
Jer