Haven't used an Android device for about 15 years. One thing I dislike the iPad is that unlike MacOS and Windows, some apps store user files in their specific locations. Often I had a hard time in finding files. How about Android tablet?
With all the options, you can make as much of a mess of it as you want. You will find that they all have predefined storage folders (or even SD if you have it) but you can many times change that. You can set up your own layout. Use cloud accounts if you want (I do to share between devices). I use OneDrive and Proton Pass mostly. Works a lot like Windows for storage and search.
Finding files, especially with search is pretty spot on.
I do not currently use an Android tablet, have an iPad, however I do use a ZFold7 much like a mini tablet, especially for my work stuff. My iPad is more for consumption than anything.
It's much easier to find your files on Android most of the time. Music, pictures, and videos are all easy to find. Other things depend a bit on the app they were made in. I have a Podcasts folder, but that is not where Pocket Casts keeps my downloads (I have no clue where they are, but I have never needed to access them from outside the app). There is a Files app for basic access to your User folder, but it can be messy like Windows and some apps can have their own bizarre folder structures or keep their files in invisible folders. But it's much more accessible than an iPad.
Android file system works closer to MacOS than the iPaDOS file systems. You have your spaces for your apps/media/documents/etc. then you have your system files which cannot be accessed by apps unless you go out of your way to allow it. The files are also not associated with the app like iPadOS
Yes setup is relatively quick and the NAS can be accessed from not only your Mac, Windows PC, phone, tablet, but your smart speakers as well as your smart TVs. This is what I have, and you would need to download an app to access your files while not home. Speeds is okay around 250mbps to 300mbps on HD and 2500mbps on M.2 so it's a nice place to store your old unused M.2 SSDs. I have 38TB and its almost full just from 4k movies and FLACs, Terminator 2 in 4k alone takes up 66GB. If you know you're not going to be home and want to shut off your internet it usually is cheaper to just pay for cloud hosting than to have an internet connection going just for the NAS. Me I have a Ring system so it's easier to just keep my internet on.
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