Android is a great solution for our users for communicating through calls and texts, however, we have a slower response time through web browsers than with other products used in the past. These issues are minimal and overall we are happy with Android products. We are unable however to use Apple Pay and other comparable apps that are popular at this time.
Debian is very well suited for application servers, web servers, file servers, hypervisors (personally, we use Proxmox for some hypervisors and this is based on Debian), and much more. It can run on various CPU architectures and scales well from large to small. We have Debian DNS servers running on Raspberry Pis, and large application and database servers running on powerful Debian installs in our racks.
If you want an OS that is rock solid, easy to manage, and predictable, Debian might be the OS you're looking for. The official packages are generally far from being bleeding edge versions, but this means that you are using packages that are battle tested and will not break compatibility at any point during its life-cycle. This, to me, is one of Debian's core strengths and a good reason for recommending it to others.
On the flip-side, the lack of up-to-date versions of various packages may be an annoyance if you actually do need to be using the latest version of such a package. If you need to be using more modern versions, you will need to remedy that yourself or look at an alternative distribution. Ubuntu may be worth a look, in this case, being that it is basically Debian with newer packages and some minor differences here and there.
Personally, I would not recommend Debian for a graphical desktop OS. You'll nearly always be better off with one of the Ubuntu flavors for a modern desktop with all the bells and whistles you'd expect with a GUI desktop.
It is very easy to use and the customer user interface is very smooth and logical. Rarely do applications crash and need reinstallation. The app store is secure enough to prevent malicious software from being advertised and potentially downloaded. Rebooting devices does not have to be a regular occurrence so this allows for high availability.
Debian is one of the most well-thought-out, logical, and intuitive Linux operating systems you can use. Configuration, package management, file system layouts, etc, are all based on many years of usage, and it's very rare to find anything surprising or confusing in everyday usage. Package management and updates are handled by APT in such a way that once configured, you can almost guarantee your system will behave as expected for the lifetime of its service. Top-notch system integration provides all the tools you'd expect from a modern Linux system, with all the stability you demand from a demanding server OS.
I've neither had super great nor super terrible support for Android. Since there are so many options within Android, their support team hasn't been able to always answer the questions that I have had. There has been more good than bad with their support so that is why I gave it a 7 instead of an even split 5.
These two operating systems are both great and can totally do everything that we need in our school. The reason we go with Android is that it is cheaper and we have a greater variety of apps available to us. iOS can be a little pricey and it also doesn't allow us to do the customization that we want.