SWTBot provides APIs that are simple to read and write. The APIs also hide the complexities involved with SWT and Eclipse. This makes it suitable for UI/functional testing by everyone, not just developers. SWTBot also provides its own set of assertions that are useful for SWT. You can also use your own assertion framework with SWTBot.
SWTBot integrates with Eclipse PDE, Eclipse headless testing framework, Ant and Tycho, so it's easy to use in your IDE and Headless Builds (as part of a CI job for example).
SWTBot can run on all platforms that SWT runs on. Very few other testing tools provide such a wide variety of platforms.
Starting from version 2.1.0, SWTBot also provide a Test Recorder and Generator that you can use to generate your test case simply by recording the UI actions as an end-user would perform them. This is really helpful to get quickly a first sketch of your SWTBot scenario and reduce costs of writing tests.