What do you like best?
Ease of use, variety of tools, and it has everything I need for my line of work which is Real Estate.
What do you dislike?
Font choice is a little limited unless I don't know how to find them... Other than that, I've used PDF Filler for about three years now and it is almost a necessity with my job.
What problems are you solving with the product? What benefits have you realized?
I've used it numerous times in Real Estate transactions to finalize contracts, revise items, and change information, etc. It makes my job much easier, neater, and smoother.

What do you like best? PDF Filler helped me when I inherited a bunch of learning material that referenced outdated case studies and I needed to update for class. Because I didn't have Adobe or photoshop, this was a great alternative to help me quickly update the decks. Erase text allowed me to "white out" the outdated information without compromising design quality. What do you dislike? If you are adding text and trying to use text box, it will show a box around what you replace. When using the text feature to replace text, of course, you won't have an exact match unless you know the current document's font and size. Nonetheless, PDF Filler makes it easy to drag, drop and align so that you'd have to really stare at the document to notice the differences between the original text and your replacement text. What problems are you solving with the product? What benefits have you realized? Needing to edit PDF's that were previously created, and provided no access to the original version. Better ease of use//less learning curve than Photoshop. Cost-friendly alternative to Adobe.