Personally, I don't want to spend the money for high-priced Adobe tools to make notes in PDFs I see from vendors in briefings. So I decided to try out one of the free download products, and the following is a quick review.

I downloaded PDF X-Change viewer from Tracker Software Products' website here. The usual process, a bit clumsy, followed - unpack, run the installer. Told it I don't want it to be the default PDF viewer. Then I opened a few PDFs to test. First impression - great speed. Second: sticky notes, text boxes are easy to find on the menu. I drew some circles around things for highlights, created sticky notes (out in the area away from the page so I could still see it - nice. Switched tools and tried the text box tool, which stays in place on the page itself - less useful if the page is densely packed. Used the search tool to find multiple references to the same thing, and quickly check if "partners" was mentioned. Worked fine. Highlighted some text, underlined some text - all works very nicely.

Finally, I saved the annotated files. Then I opened them with Adobe's free Reader. My additions were still there, and in fact the Reader tools even showed them to me in the annotations pane. I was unable to make any changes to them, but when I went back into PDF X-Change I could.

Get this product if you need to anotate PDFs. It will make your life somewhat simpler if you like to keep notes with the materials. I doubt that I'll use Reader much now - I'm setting that default.