Newbie here, but just wanted to share my thoughts since I own a 6+ and a mini 4.
Owned an iPhone 4 for about 4 years (!!) before switching to the 6+. I went for the 6+ immediately without any hesitation and loved it because the size difference was huge compared to my iPhone 4. I loved the fact that I could see so much more content on my phone, and the camera/photos look great! But I also found myself fiddling with my friend's iPad (iPad 2 or 3..don't remember) from time to time.
I've always wanted an iPad for reading comic books, web browsing and etc, but never made a purchase (I guess I didn't have a strong need for it). Had a chance to borrow my friend's iPad for a month while he was away on vacation and as I kept using it, it felt almost too big and heavy for me. Decided that IF I were to get an iPad, it would be a mini...thought it would be a perfect size for me and for what I wanted to do.
Finally bit the bullet after a few months and ordered a cellular mini 4 as soon as it became available. BTW I was deciding between the mini 2 and the mini 4. Cost effectiveness for the mini 2, but I had to go for better performance and the screen of the mini 4! Another reason for purchasing the mini was that I could do my CPA practice problems on the mini (great excuse

) since a mobile version wasn't available for my 6+. Aside from doing practice problems, here's the list of things I do on my mini 4: reading magazines/comic books, teamviewer, web browsing (forums etc), youtube, stream movies/tv shows with airvideo server HD, facebook, and CoC...I guess I'm not much of a power user compared to others here? Size is perfect for me and although I sometimes wish I had more screen real estate, it fits my needs just fine! The mini is close up to my face anyways so I don't need a larger screen.
But the thing is, since I now own a mini 4, I just don't see the need for 6+'s size. Now I almost never use my phone at home and instead use a mini whenever I'm away from my desktop. I still use my 6+ to look at my news feed on FB, read some forum posts, light web browsing and youtube. But after owning the mini 4, I believe that it wouldn't hurt to size down on my phone (was thinking about switching to the SE but decided to wait for iPhone 7).
The point is that...everyone have different needs, preferences, and usage patterns, which may change over time. IMO, there's no definitive answer to what combination of products are "the best". FOR ME, a mini 4 and a 6s or even the SE might work!! Also, you never know what works for you and what doesn't, unless you really take the time to use it.
...Sorry for such a long post! Tried to be as detailed as possible if someone was on the same boat
