Massive at 12.9", heavier and thicker than the previous Air, with a stylus.
Good idea? Bad idea? Will you be buying?
Is it really a "desktop computer" replacement?
Skip the price. Price is a secondary, if you are going "Pro" and you really NEED one, or something like it. Price will deter some/most of the market, but they aren't considered "Pro" users.
So here are the points of interest: design and function. Here are my opinions based on a person that plays piano, makes music, writes papers, writes books, draws, publishes a comic, and does spread sheets every so often. I also use email and brown the internet, and I also use lots of kitschy little apps for various calculations and tutorials, etc.
Design :
12.9" -- GREAT. The iPad Air is too small for certain functions. I own an Air and I hate using it to read documents longer than a couple pages. It is a tad small for sheet music when playing piano. I suspect the 12.9" size gets an approximate 8x11 page view--perfect.
1.5 lbs.-- FINE. I wouldn't find that size unwieldy, since this will not be utilized in the same way an iPhone would be used. Over 2 lbs. would start to wear on me when I wanted to use it as a book.
SCREEN/SPEAKERS/ETC. -- I would expect these to be fairly good to excellent, knowing Apple's current devices.
Function :
ART -- GREAT. The pencil and screen make it a low-priced and portable alternative to a Wacom. This is a very strong selling point. I have no doubt that Apple put superior effort into the Pencil and screen sensitivity. Problem: I don't think there is any current software for making art that I would prefer to use. Adobe is bonkers since they went with subscriptions, and Manga Studio doesn't have an iPad version. I will have to adjust to an alternative.
WRITING -- EXCELLENT. Pages is all I would need, but unfortunately I would have to off load documents to work inside of Adobe InDesign and Adobe Acrobat. I could make on the iPad Pro, but to package the work and publish I still need a Mac.
EMAIL and WEB -- EXCELLENT. Bigger screen means it will be like a reduced desktop, and due to the screen coming closer, the size of the screen won't be that different from a desktop.
SPREADSHEETS -- GOOD. These need screen space for complex or lengthy sheets. The larger size will help. Numbers is a good program for accounting.
MUSIC -- MEDIOCRE. While the size is best for using as a book of sheet music, composing music is hindered due to software. Garage Band can start a piece and be useful on the go, but Logic isn't available. Storage is lacking for Maschine and other Native Instruments software, and there aren't iPad versions of their programs. You can begin a composition on the iPad Pro, but you need to off load and work them up on a Mac/PC. If I wanted it as a base computer to perform EDM using Maschine, this wouldn't cut it due to a lack of software. The mobility is great, the CPU is probably adequate, the software isn't there.
CONCLUSION ....
The iPad Pro is a step in the right direction, but it is lacking in many aspects. All those items are determined by software. If there were iPad versions of certain software I frequently use, this would be a MUST purchase.
The other problem is that it doesn't appear to expand outward, using external drives or devices, the way a desktop does.
If software makers jump to iPad in the next years, perfect! Apple should really engineer the iPad Pro to flower into a desktop you can unplug. Certain programs could access large data caches on an external drive. A 512GB internal drive would be a beneficial option as well.
I believe Apple could use this step to foster a transfer of concentration into making iOS the future notebook/desktop product for most all consumers. The MacBooks could vanish, leaving the Macbook Pro for OS X users and high-end professionals. Apple makes blazing chips on their own; they are always restrained by Intel. The iPadPro has more graphic/CPU power than a 2006 MacPro. In a few years they will have an iPad with the power of modern desktop with adequate CPU benchmarks. We will see if they direct themselves that way. It might happen by 2020.
I will buy an iPad Pro, but I will still be using my desktop daily, despite wishing an iPad that would replace or surpass the desktop.