You can get more in a chest freezer than an upright.
I used to have a small 6cf and a 9cf chest freezer could fit a small elk in the small one and a big elk in the bigger one...
I prefer the upright more so for convenience than anything now. I organize stuff in beer boxes (bottle case size) or paper boxes (copy paper). Two boxes fit side by side on a shelf perfectly. I can get roughly 35-40lbs of meat in a beer box and close to 50-60 in a paper box depending how its packed.
I've had chest freezers as well and can get about another 20-30% more lbs in one of comparable size. When full they're a PITA to find anything and the freezer ends up being an unsorted disaster after a couple months. I usually have 3-4 different kinds of animals of multiple cuts... along with 3-4 types of fish, etc at any give time. I really like to be able to open the freezer and dig out what ever I'm looking for easily.
Most uprights have 4 shelves, so the smaller ones will hold about 300-350+/- and the bigger ones around 400-500 lbs. I've got a 21 and a 14cf... I put two entire AK moose in them along with a deer... had to bungy the door shut for a while.
Nice to open the freezer and be able to ball park how many pounds of meat you have left, or get an idea how much you have when stocking up for the winter.
Good luck on your elk hunt.