I was one of those complaining about not being able to loosen the cinch buckles. As others have stated, don't crank them down as tight as possible and you shouldn't have problems loosening them when needed. I have also found that even if you can't get the cinch buckles loose, there is usually enough slack in the webbing to undo the biner at the tree.
“Light thinks it travels faster than anything but it is wrong. No matter how fast light travels, it finds the darkness has always got there first, and is waiting for it."