The way I see Surface vs iPad:
- iPad: always on, instantly, ready to take your notes. Very infrequent updates, long battery life. Pencil requires frequent charging, unfortunately. Otherwise zero maintenance, automatic iCloud backup, you'll never lose your data even if you're not very good with computers and backup. Very secure by design. These days you can edit photos, even video, but it's no desktop replacement for me, due to the lack of mouse support (I'm an old-school desktop person).
- Surface: It's beautiful, I love it that it runs a full desktop system, photo editing, software development, you name it, no limitations. But it's a Windows laptop, with constant system updates and reboots. It is high maintenance (comparatively), and the last thing you want is system maintenance when you whip it out to jot some equations down, or sketch a doodle, or browse Instagram. You need to worry about your own backup, and there's nothing like Time Machine for Windows, not even close. There's Backblaze and other solutions, but not as seamless, and requires deliberate effort. The latest Windows Update deleted many users' documents, pictures, downloads, music. I'm a Windows developer, I know how to use Windows, but there always seems to be a nagging issue when you're very busy with something else.
So Surface is much more powerful, but it comes with the higher maintenance, and the iPad is more like an appliance that is always on and ready to go. The iPad has unmatched security due to lack of file system, highly enforced sandboxing (= app isolation, or walled garden). Windows is the usual, you constantly need to scan your files in the background for malware, which uses battery, and the average nontechnical folks can seriously lose data or get infected my ransomware if they don't know what they're doing. If Boeing got infected, anyone can be. You have to install and manage your own backup solution as well. Only Windows Pro comes with full-disk encryption, which is standard on every Mac and iPad. So pros and cons on both sides, very different devices.