What do you like best?
As a Realtor, my whole business is based on electronic documentation. PDF filler is kind of named poorly, because it really is a PDF editor. It allows you to easily change almost anything on a pdf document...across both desktop and mobile platforms. It simply works as you'd expect it to...every time. I use it practically every day.
What do you dislike?
I wish there were better tools for generating lines (how about a toggle into and out of orthagonal for a line?) It should allow deeper zooming with a thumbnail view showing where you are in the overall document. I like my pdfs to look perfect and sometimes these limit me in that goal.
What problems are you solving with the product? What benefits have you realized?
A Realtor literally lives or dies on his/her electronic documentation. This tool lets me master the changes that inevitably occur with documents. I use it every day.

What do you like best?
Changing things (like dates) on insurance forms helps us a great deal when the insurance information stays the same and only the date needs changed. (Accord forms). We don't have to completely retype an insurance renewal form. So Handy
What do you dislike?
I have helped a colleague in inputting his information on flyers that had someone else's and the eraser showed lines in the final product. I had to figure out what was going on and I figured out I could increase the eraser to remove items rather than going over it several times (like wite-out tape).
Recommendations to others considering the product:
If you need to make changes to documents that you do not want to retype over and over again, then this product is a handy tool. Also, for doing 'already-made-up-flyers' to use for yourself by adding your own information is great. I used to have to remake everything with Corel Draw. This is waaaaaaay easier!!
What problems are you solving with the product? What benefits have you realized?
Non really for what I use it for.