The 12 inch macbook is for those people who just have a smartphone like iPhone 5S/ iPhone 6 or 7 Plus.
But it's totally not worth it if you already have an iPad since it will be TOO CLOSE in size especially the iPad 9.7 Inch. Now, if you have an iPad Pro 12.9 Inch the Macbook 12 inch will shrink in size dramatically.
Even the Macbook 12 inch is only 2.1 times bigger than the iPad Mini. While the iPad Mini is about 2.4 times bigger than iPhone 7 Plus. See!??
For those who have an iPad Mini, you should buy Macbook 13 inch
For those who have an iPad Air 2/ Pro (regular 9.7") Macbook pro 15 inch is your friend
FOr those who have an iPad Pro 12.9 inch, then a Macbook Pro (2012) 17 inch or an iMac is what you needed.
I bought the 12.9 iPad Pro but felt it was too similar in size to my 15" MacBook Pro so sold it. I then missed the 12.9 iPad Pro so bought another!