I spent an afternoon in a ground blind for the first time last season with my son and a "guide" at a State sponsored Youth Hunt.  I was pleased with the result.  Three of us in there, moving a little, talking quietly, sitting on chairs and upended buckets, sturdy rest for the rifle, watching out of the screened windows, not affecting the movement of the deer. 
I believe a ground blind not only gives great cover and shields the hunter's movement, it also blocks some distribution of scent.  If the deer are moving you can put up a ground blind fast and easily near their path.  That isn't done with ladder stands.  Perhaps the tree climber boys will chime in too.  I don't use a climber.  I almost always use a ladder though.  
I have been poised to purchase a ground blind.  They have their distinct advantages.  In particular - portability.