Having used Wire-O to bind various items I found these ProClick Spines very easy to use, open, re-close, and trim. They are different from anything else I've seen, they have a unique, clean and contemporary appearance. They also allow you to use the remainder trim on another piece without the apparent break you would expect to see with other binding systems. I would however like to be able to access other colors.
Each year I create a family calendar that includes recipes, birthdays, anniversaries, etc. I use these spines with card stock and give the calendars as Christmas presents to everyone. These are very durable, I often receive used spines back which I will re-use to create the next years calendar. I have been using these for so long that I can't even remember how I bound the calendars before I found this product.
I produce training workbooks. The pro-click spines are far more professionally looking than the regular GBC bindings. They let the workbook lay flat.
Main advantage is that you can open them and add more pages. Some of my books are not used constantly and when I need them, there has often been a software upgrade.