What iPad Pro were you considering.
If you are looking to use one of these as full computer replacement like a mobile laptop replacement, the 32 GB model will be a poor substitute with its paltry storage amount which leaves you with only the much pricier 128 GB model to consider.
In the near and, practically $1000 cost of that iPad Pro model, there are full blown Macs that run OS X that are more powerful than the iPad Pro.
iPads and iOS are not yet ready to really call themselves computer or laptop replacements and this stage and time.
I can easily see this changing in a couple of years. Just isn't here in the now, as yet!
So, for the $1000 range and if you can scrounge up just $200-$300 more there ars models of 11 inch screen and 13 inch screen MacBooks and MacBook Airs that are $1000 to $1200. Plus for $1300 there is the gorgeous 13 inch screen retina display of the MacBook Pro that are a LOT more capable mobile devices than an iPad Pro.
AND, there are two baseline models of 21 inch screen iMacs that come in at $1100 and $1300, respectively.
I have the iPad Pro 128 GB model.
I absolutely love this thing as an artistic device and tool and, ironically, I try to use it as much as I can as a laptop replacement, too, but, in this respect, it has limits that a true laptop running OS X won't have (touch interface ignored for comparisons).
I cannot create as well on ANY iPad what I can do very well on my Mac. I would never try using the current crop of any mobile device or iPads as a full computer replacement.
Even with my iPad Pro, it will take me awhile to get my drawing chops up to my own acceptable level, but my drawing style and work, to date, will still be quite a bit better on a full blown computer with more "professional" drawings tools, more accurate and finer resolution drawing tablets and stylii and, generally, more powerful desktop/laptop computer apps that offer more options and finer working resolutions that I fully take advantage of in my drawing and design work.
An iPad as a powerful adjunct device and/or tool to a desktop or laptop computer? Yes, but not a standalone only computing device, currently.
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IF, IF Apple had the 64 GB iPad Pro option, you might have gotten away with that storage amount, but even THAT amount dwarfs a regular computer for onboard storage. MacBook Airs, in the price range of an iPad Pro 128 GB model, come with double that storage amount with 256 GBs of flash storage for nearly the same price as an iPad Pro!
If you still decide to go iPad Pro, you really need the 128 GB storage version if you want to store a decent amount of data onto the device
Especially if your iMac had a ton of stored data on it.