I have used Breakaway fastlinks for several years with no problems at all. This year I started using a similar product from a company called Backlash. Slight modification makes it easier to use AND it comes in a XL (150 lb.) size. Even better than the Breakaway IMHO.
Here is a link. Scroll toward the bottom to see the clips.
http://www.backlashsportfishingusa.com/tackle.htm