The 1/8" of play that several people have complained about is easily solved.  It took me a while to find this out, but the locking lever has THREE positions.  When the lever is above guide, the clamp is unlocked.  When the lever is parallel with the guide, the clamp is locked but the guide can wiggle about 1/8".  Some people stop here and think the wiggle is a defect.  But the lever has a THIRD position, below the guide.  In this position, all the slop is gone.  When the guide is new, it is sometimes difficult to get the lever in this third position.  You may have to press down on the handle.