It is the only tool that I use to create logos. It gives me the flexibility to create sharp text and marks and they can then be resized at will, color changes in a second and perfect way to export. I know that some people use Illustrator for document layout, it is not ideal. While I can easily create documents here, it really is InDesign that is the perfect tool.
If you have high resolution images, it does a remarkably good job at resizing and resampling. It has to have something to work with, so I recommend it only be used on good quality images. On four to five megapixel images, I don't think it works as well as on my 20+ megapixel photos.
While Adobe Illustrator CC is one of the only true design software out there, it really stands heads above the other products. It's clean UI and menu structure is easy to navigate.
There's a bit of a learning curve to this software vs other similar tools that can take some time to learn and get familiar with but the amount of functionality that Adobe Illustrator CC offers is quite large compared to simpler tools.
I normally already know how to do whatever I'm trying out, but the documentation (as well as a simple Google search) makes any question quick to resolve. The Adobe boards themselves are a fantastic resource, especially for resolving questions between new programs and iterative releases.
Topaz always responds to my questions in a few hours or a day at most. They've been able to explain their answers and give detail I needed to complete my work. Their instructions are quite clear and easy to use. I haven't had to reference any third-party support sources to get answers.
I chose Rhinoceros 3D because it is accurate to make drawings in it and it is better to make drawings in Rhinoceros 3D and then put them in Adobe Illustrator. But while printing or scaling it is much easier to put it in Adobe Illustrator. This makes the whole printing aspect of it much easier.
Since they aren't direct competitors I don't expect PaintShop to hold up to a specialized piece of software. PaintShop allows you to resize but it's not intended to resample as well as Gigapixel AI.