Three months ago I began an experiment to discover for myself how well the 12.9 iPad Pro (gen 3) with ASK could replace a Mac laptop, used alongside an iMac and a Windows laptop (which I need for occasional but essential tasks).
The answer is very well. There are a few tasks I can't do on the iPad but the Windows laptop can do them when away from base, or the iMac at home. There is some frustration learning the iOS way of doing things. It requires some effort pitting in to learn to use it.
However the real point of this post is that three weeks ago I replaced the Windows laptop with a Microsoft Surface GO (128GB with 8GB RAM version, with 256 GB microSD). I have switched it from Windows 10s to full Windows 10.
Not fast, but it does everything I need of it and for me quite usable. I believe there is no other device that runs a full desktop OS on a 10 inch screen. As a tablet the iPad Pro is much nicer to use but I do find myself using the GO instead of the big iPP for Kindle reading sometimes.
It has made realise how utterly wonderful it would be if I could run macOS on my iPP and have trackpad, mouse, external USB-C storage etc
Since using my Surface Pro 6 (due to the fact Apple haven't fixed the keyboard issues on MacBooks yet) i have found it to be more useful as a laptop! i still love to use my iPad Pro and iMac. Apple devices look better and the OS (both MacOS and IOS) are cleaner looking and more refined. That being said there are things i like about the Surface such as the kickstand, being able to adjust it at any angle is really useful.
I'm an Apple guy, i have been since 2009 when i had my first iPhone, however i do appreciate the Surface line up more just lately. But if i had to choose between a Mac and Surface i would still choose a Mac every time.