There are sevral brands of these, Hair Locs, Babe, Monkey Barz, Rockstar hair, just to name a few. The hair is the same quality or type of hair they offer for regular glue in services or for track and sew The difference seem to be in the application with the small bead or ring.
We just started using them and haven't noticed much difference in wear, they are much, much easier to remove than track and sew or glue in. It can be a more expensive way to put extensions in if a client has very thick hair to keep it looking nice. The average head takes between 17 and 25 packages of hair. Once the extensions are in the hair has a pieced out layered look.
There are pros and cons to either way, the ring extensions are very easy to apply and maintain. The choice of application should be based on the finished look. Choose the application that will get you the closest to your desired look.