HERBENUS, I certainly agree that a full chest type freezer is a little harder to rummage than a full upright but not by a large margin. Like the grocer's chest style freezers (with no lids at all) a chest style freezer will lose refrigeration so much slower than an upright that rummaging 10 times as long would probably not lose as much cold as the upright unless you have a terrific draft blowing across or into the chest. Note: you don't see upright freezers without doors.
Still, there are perfectly good reasons for uprights that might outweigh all energy cost/efficiency considerations that favor the chests. Footprint certainly is a consideration. If there just isn't a convenient space for a chest but you need/want a freezer, then there you are.
I recently saw a frige with a decent size freezer. It looked pretty interesting. The frige part had equal sized doors (like french doors) on top and a pull out freezer drawer, a mini-chest type freezer if you will, in the bottom.
Of greater importance is what you put in the freezer. Fish that you caught, game that you harvested, beef, poultry, etc that you raised, vegies from your garden, berries and fruit and so on. Hopefully not a bunch of plastic food comprised of sat and trans fat, and prefab factory built pseudo-food the majority of the cost of which TV advertising.
Best to you,
Pat