I use these primarily to clean my backyard (3 dogs).  As such, I'm usually picking up multiple... well you know... at one time.  The double thickness of bag makes it more durable and prevents unpleasant rips or punctures.  However, the design isn't great.  I've found that the end gets a bit crumpled, and it would be better suited if it was designed like an actual "mitt" with a separate thumb cavity so that you could get a better grip, etc.  Otherwise, I've been very happy with them.