What do you like best? Editing, merging and marking-up PDF documents and particularly drawings (I am an architect) is easy to do on the program. Editing, deleting selected pages and merging are the most common features that I use, and this is easily done on pdfFiller. It would be helpful if the program has better ways to draw lines and circles, etc., as these are basic needs when marking-up drawings. These features need to be improved. What do you dislike? Drawing features are not user friendly and need to be improved. Highlighting, which is available on pdfFiller, can only be done in straight lines and not at an angle or in curved shapes. This needs to be improved. What problems is the product solving and how is that benefiting you? Editing and merging PDF documents, marking-up PDF drawings. These are my most critical needs for document review and pdfFiller allows me to do all of this easily.