If there are coils in the shelves then its pretty difficult to use. You have to bend them out of the way and really risk rendering the freezer useless.
The frost free type usually don't have coils in the shelves and the shelves are movable/removable. They tend to be more expensive too
Of course since cold air sinks, even if you open a chest freezer the cold air stays in there. With an upright as soon as you open the door the cold air starts flowing out