What do you like best?
The software is good at building API documentation. I was using it to document C# projects. Once you grab all the .dll files and the accompanying XML documentation output, it will build the help project from these files. You can see what the developers entered as documentation with the option to overwrite their comments with your own without changing it in code. That said, there will be frustrations as you try to find the one DLL not included in your assemblies folder using the often cryptic error messages.
What do you dislike?
The most glaring shortcoming of this software is the poor documentation. If you want to customize the output of your deliverables, there is little to no help. Their documentation seems to be focused on videos that are rarely helpful and that do not have a table of contents or other mechanism to scan the content. You end up spending several minutes to confirm the video is only helpful for the most basic of tasks.
Customization of output is very difficult for the reason just mentioned. I was able to extend the functionality of the webhelp projects it creates, but did so only by fumbling around in the dark.
PDF output is not very good, although it's improving. Styling the output of PDFs is quite a nightmare.
The files are not saved as native XML. If you plan to move to another authoring system later, I imagine there will be a large conversion effort required.
Recommendations to others considering the product
Look elsewhere if you need easily configurable output and XML files. Support is often very responsive with feature requests and bugs. Of course, you will have to pay for the support to keep getting these features.
What business problems are you solving with the product? What benefits have you realized?
We have many complex software solutions that require documentation for different user types (developer, user, administrator). As with most single-source authoring software, this one delivers webhelp projects and .chm files from the same source material, but the end result is adequate at best and downright poor if you need PDF.