he was slightly correct.

it is true, to some extent, or to a great extent, depending on how you view things, that a manual defrost chest freezer is the best. Since you already have one, you have the best of both worlds. Use it for what it is: the long term storage fund. Then, in addition to it, get the frost-free one. It will cause daily temperature swings, which you won't see but your foods will show it, some more than others, some faster, some slower. It all depends.

There are some models of "passive cooling" freezers that are upright. To avoid letting in a lot of moist room temperature air when you open the upright freezer door, it is best when the freezer shelves are occupied by large bins or drawers.

hth

A lot of it depends on the technology involved. Because of the geometry, a chest freezer is the best for long term. Next best is an upright manual defrost freezer with freezer coil shelves (if you can even get one anymore that isn't a lab freezer). That's where each or most of the shelves have freezer coils either inside or underneath the shelves. Next after that is a manual defrost with ordinary shelves, and last is a self-defrosting. BUT, the higher end no-frost freezers use different technology than the self defrost freezers. They use an evaporator to remove moisture from the box before it has a chance to form frost, rather than heating it to get rid of the frost. I don't understand how these work, but the heating doesn't happen in the freezer box so your food doesn't melt and refreeze.

I've only been using my new freezer with evaporator for about 8 months, and I'm using it for daily use, including ice, so don't know how it would do for truly long term. It's very fancy (Miele) and has things like a super-freeze setting so that if you're going to be freezing a lot of things from room temperature you can cool it down first so that what you already have frozen doesn't warm up too much from the "heat" in the new things. I've used it a few times, and I'm not sure superfreezing and raising things back to 0 is all that good for them, though it's an interesting concept. So far so good. It's at least no worse than my old GE coil shelves upright (which I have in the garage now for true long storage).

My only experience is with an upright freezer - we've had a Sub Zero in our kitchen for 23 years and we've never had an issue with the quality of food. We seldom keep food for over a year but as long as the item was properly wrapped it keeps well. I tend to be very organized and all the packages in the freezer are labeled and dated. It's really easy with an upright to check on what's inside and to use the older items.

My brother has a large chest freezer and he keeps things in smaller metal baskets so that he can find them quickly. He has one basket with duck, another with chicken, one for pork and I swear the entire bottom is lined with deer meat.