The UI is outstanding and very effortless. Very impressed. My only issue was with advanced features. Would have liked to know ahead of time that they were additional fee. Everything looks included and don't like being told something cost money after the fact. Second, when telling me I had to upgrade to get additional feature, it should show the difference between what I am paying verses the new amount. I was on personal plan ($6) but to get the features I needed it was ($10). It said it was $10 for advanced plan but I didn't know if that meant $10 MORE than I was already paying. I had to open site in incognito mode, look at plans to figure it out... not fun. Lastly, I was trying to send 2 separate PDFs as one doc. It took me a while to figure out where Merge was. I didn't understand why all the options under Actions were greyed out. That was very frustrating and should be improved.

A feature that is critical to my business broke on Friday. I was able to interface and get updates about the fix over the entire weekend and had the problem solved by the dev team before Monday morning. Awesome teamwork from the folks at PDFiller from end to end. Highly recommend.