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?
The program is easy to use and super convenient. Your documents are always with you on the server PDFIller provides.
What do you dislike?
Getting in touch with a person in customer service is impossible and emails to cust. serv. have not been answered. I originally signed up as a single user; but then as my needs expanded at my office, I added and paid for three more users. For a while everything worked without issue, but then the other three users could not log-in and the different prompts in my dashboard were saying the subscriptions were active and to this day my office staff works through my sole account which can knock someone off in the middle of something.
What problems are you solving with the product? What benefits have you realized?
The fax benefit is awesome. I use the program with my insurance agency. It is way more user friendly than Adobe and you don't need a separate service to send a client a form to sign.