The best C# PDF SDK to Modify Field Validation PDF

Very limited use so far. Can't figure out how to select another form, either of the same type just completed or a different form without going back to the start page manually. Otherwise so far so good.

There was one issue- the orange pen would pop up when highlighting a word or sentence, suggesting an edit I assume. I would click it then stare at a blue circle waiting waiting waiting. I would just close the entire website and come back.

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.