Short:
Simple word files can be done in pages. I have no experience with it (I have "free" office from university) but my wife does everything with it.
Reading and annotating on the 12.9 has really "saved my life". (PDF-expert with documents 5, GoodNotes, notability, others, many threads about that in this forum)
Watching movies is a pleasant experience decent sound (a good set of headphones might be better, but the 12.9 has really decent sound when you consider the dimensional constraints).
Screen between Macbook 12 and 12.9 I don't know, but the 12.9 is really, really good.
what would you need the windows for?
Not to bash or anything, but unless you need to use Windows-only software, edit large excel files, need to run OCR or write code (and not just websites) there aren't many reasons to own a laptop if you have an iPad Pro 12.9. Backup can be done on a USB-lighting stick or in iCloud (I use icloud, others use a stick) there are very few occasions when you need a laptop.
Be aware though: it takes time and effort to do everything on an iPad. Not because it can't be done, but because I was set in my ways about doing things. You really need to reinvent how to do things at times. Had the same when I switched from Windows to Mac some 10-15 years ago, now again when I switched to iOS.
Long story:
I started my study at law school end of august 2015. and we do have to read such an enormous amount of PDF's, web based books and all. Think about 1500 pages per 4 weeks in the first year and now around 25000-5000 per 4 weeks. And it ain't comics, it's serious stuff. (BTW comics are brilliant on a 12.9
)
I waited with buying an iPad until the Pro came out in November 2015 and borrowed the Air 1 from my father in the mean time. Switching to the 12.9 was a game changer.
I know many people prefer reading old "real" paper books. And if I would be still on a laptop, I could fully understand why. Books have been written for centuries in portrait and for good reason. Books have been written with lettertypes that have serifs, and for good reason. Good books have a specific layout that is just right, that is enjoyable to read and have centuries of refinement behind it.
For the last 20 years I've been reading on fuzzy CRT monitors and later on just as fuzzy monitors. These where so bad that you needed sans serif lettertypes to not get a huge headache. The monitors where tiny, cramped 11" 640x480 pixels in landscape. Webpages had usually a pretty horrible layout. If it where (scanned) pdf's all was wrong: they where designed on paper and usually with serif lettertypes to be read in portrait, so you couldn't read more than half a page on your monitor. Things got even worse when there where diagrams, photos. Not to mention the horrors of reading articles in three columns, so you where constantly scrolling up and down, around images, $%^&*#@!
Many people that still prefer the paper books are amazed when I lend them my iPad Pro for an hour or so. I have a collection of (older) ePub magazines. So they have a nice interesting piece to read. It's almost always the same: they tend to get into the story they are reading and enjoy it seriously.
Then I ask them to try a good book in iBooks and the same happens.
So if you are reading really a lot, of colluded articles, (scanned) PDF's and websites, the iPad Pro 12.9 is brilliant. If you type text and don't like on screen keyboards, the Apple Smart Keyboard (ASK) is good. For the connoisseur it might not be a traditional laptop keyboard, it isn't a mechanical switch keyboard either, but I can type blind and get good speeds on it. It's also thin and out of the way. And expensive at $179(?) But worth it when you type enough and want a really portable option. A bit less portable (but still not that chunky) is a K380 Logitech keyboard. It can quick connect to 3 Bluetooth devices by using 3 buttons. It's $40 and feels nice.
If you do annotating, think about the Pencil. With the pencil you can use apps like PDF-expert, GoodNotes or Notability to make handwritten notes and annotated pdfs. Liquid text and others to make summaries quick and easy. Nebo let's you hand write and translate your writing into legible text. I started using Coda for maintaining a website and it's easy, quick and pain free (but expensive, there are cheaper or free code editors).
Getting back at MacBook or iPad Pro 12.9: if you want to continue the CRT tradition of landscape displays that feel cramped (be it with much, much better display) get the Macbook. But if you want to be part of the future, go with the iPad.
But honestly, even after well over 18 months of the iPad Pro 12.9 I still really enjoy the idea of reading on it. I can chuckle a bit when I see others read badly scanned PDF's on laptops. Poor sods.
Sorry for my long rant. But I do hope it helps.
