1. It's open source which supports range of languages, operating systems and languages. Well suited for Android and IOS mobile automation. Supports all kinds of apps, which makes it flexible and robust mobile testing tool 2. It is less appropriate where we need intercept network call to verify the API calls. Extensive coding experience is required to work Appium
Good for simple requests, simple scripts, assertions, and small workflows. Also not bad with the Open Source version if savvy with code as you can do a lot with custom functionality.Free version has limited compatibility with scripts/projects created from the Pro version, but functionality-wise can probably be made up with coding. As such, the free version may not be too suitable for complex scripts or for those who are not familiar with coding as functionality/usability may be limited.
I would like to give 9/10 rating to Appium because of it can easily integrate with popular frameworks and CI/CD tools, as well as it is reliable, flexible and easy to use. The setup can bit complex in initial step, but once on configured it's very easy to use and enables stable and scalable mobile automation for real and cloud devices.
If you're an Apple developer, you use Xcode. It's practically a forced necessity. For system testing though, it doesn't have to be. You can have your development team focus on unit and integration tests in their platform and another team automate acceptance tests with a language they are more familiar with.
Compared to SoapUI, we have been using "light" tools like RestClient extension in Firefox, or Postman. Compared to Postman, SoapUI is more simple for WSDL / SOAP webservices, as SoapUI generate all envelop, but Postman does not. For Rest API, I think that Postman is a little above SoapUI, but not too far away.