pdfPen was mentioned in another thread, and I’m intrigued. I downloaded the demo, but wanted some feedback from the Scrivener community (Scrivenateers? Scrivenators? Scrivenerati!)
Anyway, use it? Like it? Worth it? (Fifty bucks!)

It’s fifty bucks? o.O

I still have it on demo, but I thought it was about 17 or so. I like the multiple colours for highlighting, as I read a lot of academic PDFs. The change does you good, and it makes for easy sorting of information later.