I love that I can alter a pdf with just about anything. I can also send forms to my clients to e-sign through a secure site. Often I use it to sign documents that are sent to me as well.
What do you dislike?
The only drawback that I have is if I upload a document and want to use it for different customers, it doesn't save each one individually.
Recommendations to others considering the product:
What problems are you solving with the product? What benefits have you realized?
If I can't get a real-life e-signature I turn to PDFfiller to get the job done. My clients benefit from the secure site when I send sensitive documents to them.