That much power comes with a price. Unlike Visual Basic, PowerBASIC does not provide a particularly easy means of creating a user interface. It does not as conveniently handle the details of responding to events. It does not aggressively protect the user against coding/execution mistakes. And it requires more attention to detail during the coding process.
Visual Basic programmers will be disappointed with the less sophicated IDE - particularly with the awkward split between the source code editor and the GUI creation tool. They will also be surprised/disappointed with the lack of intrinsic database tools.
In return for those inconveniences/limitations, you get power and you get control over the finished product to a degree not available with any BASIC dialect and which rivals the results of any other language.
Is it worth it?
Judging by Google search results, there might be as many as a half dozen BASIC dialects which are more popular. If all a programmer needs to do is create a simple user interface with some simple code behind it, then other BASIC dialects can more easily satisfy the need and provide a shorter learning cycle.
On the other hand, those who use PowerBASIC regularly seem to be fiercely loyal to the product. I've found that first time users tend to shy away from it whereas more experienced programmers are drawn to it.
For the most serious programmers, who want precision control over their finished product and want to get the most performance possible from their applications, the answer seems to be YES! - It is worth it!