Given that the iPad has become my primary computing device at home (as opposed to work) and since serendipity meant that a bank sent me a cheque last week for an overcharging that happened over 6 years ago, and said cheque was more than the price of an iPad Pro...
I felt it would have been rude not to!
This is day 3 of Pro ownership. Minutes after setting it up and starting to use it, my Air 1 felt tiny by comparison. Here they are along with my wife's mini:
It really is an iPad on steroids. The 4 speaker sound system is awesome - it is so much more powerful than the old, single speaker system, and with genuine stereo sound it transforms media presentation, music and gameplay. The bigger display also means that apps which were previously a bit cramped on screen start to become a lot more usable. For example, I quite like strategy games and loads of these have been ported to the iPad, but where really tricky to play (for example, Settlers). They are now easy to work with on the Pro.
The screen is pretty much identical to having two Airs side by side:
The device is surprisingly light. You can certainly hold it in one hand when it is resting on your lap, for example, and use it that way for an extended period. The two part case (cover and case need to be bought separately) is excellent; it feels a better quality than the older, one piece smart case for the Air and it gives better protection, too. My Air case gaps near the hinge. The Smart Cover is flush to the screen throughout when closed, and also magnetically clips itself open when fully opened against the back of the device. You can still use the cover in 'triangle' configuration as an effective stand and it is just as stable as the Air would be.
The device is a powerhouse, as you would expect, and split-screen multitasking works fantastically with apps that support it. That is the current limitation - apps need to be updated to make use of the new screen estate and capabilities. For example, the Pro's keyboard has many more keys including a number row and most punctuation characters immediately available. But if you are using an app which has not been updated to make use of the Pro's capabilities you get a slightly enlarged version of the regular iPad keyboard instead.
Similarly, non-optimised apps rely on scaling to make the app fit the screen. One of my use cases is reading PDF manuals which typically are formatted as A4 or US Legal in size. Using PDF Expert (optimised for the Pro) they are crisp and a joy to read. My preferred PDF app (GoodReader) is not yet optimised so whilst the PDFs are bigger than on an Air they are slightly fuzzy. I'm sure many more apps will be optimise for the Pro in the near future.
I didn't bother with the Apple keyboard cover accessory as, personally, I think people who attach physical keyboard to their iPads are missing the point. In my opinion, if you need a keyboard you probably want a laptop. The add on keyboards for iPads add bulk and detract from the tablet strengths of being usable in different orientations.
I also didn't bother getting a pencil, but based on the video reviews coming out I think I might invest in one of these in the near future. I'm not an artist but I do traditionally use my iPad in meetings a lot, so it might be cool for note taking with the right app.
For now, I have kept my iPad Air 1. I'll see how much the bigger form factor impacts portability over the next month or so then make a decision one way or another. I used to carry my Air around most of the time, and whilst the Pro is still very portable it is obviously less so than an Air.
I know it is contentious to say that
any iPad could replace a laptop, but keeping in mind the fact that the vast majority of people use their computer for the web, email and maybe a simple game or two I think that is totally believable. People like us who use computers
at home for more than these simple things are the exception rather than the rule. And I would say that the iPad Pro is as close to a high end laptop experience as you can get with a tablet right now.
Dave 
