I'm a Quark XPress lifer!
What do you like best?
The ease of setting and manipulating type/text. I work in a text heavy industry and being able to set text quickly and without struggle is critical. This is one of the biggest edges I think Quark still has on InDesign.
What do you dislike?
That you can't have different layout sizes within one document. I work with a lot of digital display and it would be easier to be able to have all of my ads within one document. 300x600, 728x90, 1200x628, etc. This is one area where InDesign has an edge. (please take note and work on this!)
Recommendations to others considering the product:
This is a great application that will give you just about everything you need in a layout program. I tried to make the switch to InDesign, I did...the industry is really pushing us designers that way but I have to say I don't get it. I've been using Quark now for over 25 years and it's still my go to.
What problems are you solving with the product? What benefits have you realized?
The benefits of Quark are many. It's user friendly and adds great new features with each update.