The operating system for your visitor management system isn't too important but how well the device fits your requirements and budget is often dependent on what's available and this is often dependent on the operating system. For example, you might want a low cost tablet with a big screen, in which case, an Android tablet might be great. But, if you want a fob or card scanner and a printer, you might struggle to get an Android tablet with power and usb sockets to do what you want, the Microsoft Surface Go might therefore be a better fit.
Alternatively, you might want to make a statement in reception and use a 50" touch screen, in which case using Windows or Linux might be the way forward.
The Raspberry Pi might also make sense as the low computing power required by DigiGreet is more than covered by the Pi and you can fit a Pi screen into a custom unit which has your branding on, or needs to be waterproof because it is outside, or needs to be inside a robot to walk around welcoming guests... the possibilities are huge and DigiGreet has the flexibility to meet your needs.
Please note that our default recommendation is the Microsoft Surface Go at around £320, it's reasonable, has all the ports you need and most people are familiar with Windows. We've had a number of clients struggle to hook a printer up to an Android, so wouldn't recommend an Android if you want to print unless you are sure you can reliably connect a printer. Similarly, an iPad puts large print margins which aren't great for a badge, so we tend not to recommend them either.
Once you know what you want just let us know and we can chat through the options.