I have a iPad 4 & wife has an original iPad Mini and we've been thinking about upgrading. I've been thinking about the new iPad 2017 for me and either the same for my wife or a factory refurbished iPad 4 Mini. Will I notice much difference in the physical size and weight of the iPad 2017 compared to my iPad 4? Will the screen itself pretty much have the same look & feel? Does it make sense to invest in a refurbished iPad 4 Mini vs the iPad 2017 (about $50 difference)? Both our iPad's are pretty sluggish at this point does anyone buy these and if so what are they worth?