On the odd occasions I've come across these things, a couple of points strike me:
- Doors are huge and bulky, for no apparent reason in some instances
- They're too skinny: No room for anything remotely large (i.e. bulk purchased meats, pre-packed products etc)
- They're really, really deep: This compounds 'skinny.' Its all crammed in tight and then you have to stand on the tips of your toes to get to the stuff in the back, or pull everything out in front to get to it. With the door being open so long, the energy use is increased substantially
- Usually fitted with gimmicky "thru-the-door" features, which also use additional energy and add more things to go wrong later on.
Personally, if I wanted an SxS, I would opt for a French door model since there is actually ROOM to play with. Of course, these things come with additional "drawers" which presumably increase energy consumption even more.
In reality, however, SxS models are the highest energy consumers out of any fridge.
I guess its a combination of the small space (where the cold air falls out the minute you open the door), gimmicky features and perhaps other reasons too. Those "features" can also become *nightmares* as the fridge ages.
They would be the last choice on a refrigerator shopping list. An upside-down, pidgeon-pair or a mix and match with a chest freezer would be first considerations, as they're cheaper to buy and cheaper to run. Win-win!
If you need a fridge and freezer in a tight space, get an upside down or perhaps smaller refrigerator and a little chest freezer to tuck away in the garage, for example. These choices use FAR less energy and don't have as much inconvenience built into them by default.
So, in short: The only "advantage" of an SxS model is that it comes with a lot of disadvantages. I can't see any benefit of this design.