Adobe Illustrator is used to help make drawings look good but not make them. It is easy to add color or texture but it is hard to actually make the drawings in it. I would recommend using other software to make the lines for plans and sections and using Adobe Illustrator to make it look good.
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.
Illustrator has become easier in recent years to use with more intuitive tools and controls for them. Illustration software has improved but Adobe Illustrator has kept up and keeps the edge with its extensive toolset. Newly added collaboration tools with Adobe make it even better and the expectation is that is to continue.
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.
They complement each other, each with its own specific characteristics, but within a marketing sector, an experienced designer knows that the use of these tools in sets makes all the difference. It is possible to combine their uses and create really relevant materials that will bring a great return to the company and in the dissemination of arts with superior quality to the competitors
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.