I have a Macbook Air so having a big iPad doesn't do it for me. On the other hand I believe that the UI of an iPhone is better suited for small devices like the Plus and the iPad Mini. I am no talking about completely replacing the iPad functionality with an iPhone 6 Plus, but since I already own a Macbook Air, I am only interested on the small tasks that an iPhone or iPad can accomplish:
Social networks, mail, reading, playing games (not that much though).
Well, I have an MacBook Air too, because sometimes I need the horsepower and flexibility. But using the Air in bed at night is uncomfortable as thin and light as it is. It still has a physical keyboard.
So if you break down the tasks you do on a regular basis, perhaps you can make it work. But if web browsing is one of them, the Plus is just not going to cut it. Email, apps you may need, great. But Safari or Chrome on such a small screen is painful. Can you make it work? Sure. Do you need to? Not if you have a much bigger and nicer screen of an iPad around.
Reading is ok on the Plus. I tried it, and was ok. But I have a Kindle Paperwhite for that and went back to it. Extended reading is something eInk will trump LCD every single time. But if I didn't have my Kindle with me I could read a few chapters on the Plus. No problem.
I played some Infinity Blade III on the Plus, and was amazed on how smooth it was and how good it looked. Gaming on the Plus is a lot of fun. Can't wait to try some flight sims or racing games.
Reading PDFs is a bit uncomfortable, for the same reason browsing the web is. A lot of pinch and zooming. Me eyesight is not what is used to be, and I am spoiled by the iPad Air screen. That's where the Plus (or any other smaller device, even the Mini) falls short.
If my iPad Air broke tomorrow, could I make do with the Plus? I think I could for a while, while the iPad Air 2 was launched.
