> Supermarket fridge/freezers are opened too often for them to care.
While that's true, most merchandiser refrigerators (as they are known - also "display coolers" is a term) use dual-pane glass on the doors (and I wouldn't be surprised to find triple-pane either).
I've been looking into one of these for a while now; my wife and I want to get one to replace our current side-by-side, because we hardly ever use the freezer side, and we already have a chest freezer in our garage anyhow. The problem hasn't been the cost (commercial fridges aren't really much more expensive than consumer units), but the size - they are too tall for the area we have (without mods to our cabinets). Of course, we have found that new consumer fridges have the same problem!
Our house was built in the early-1970s (block construction, copper wiring and water pipes, and no HOA - so if I want to weld in the front yard on my vehicle while it's on jack-stands overnight - NFG), and so it has the old-style "crappy cabinet over the fridge" area - so we are limited by that, unless we take it out - which may end up being the solution.
The only other downside to a commercial unit is the fact that the warranty is instantly voided if you buy one and install it for home use. Furthermore, service is more expensive (part, labor, and the whole nine yards). Still, it should be more reliable in the long run, which is what we want. We did the same thing recently with our microwave, purchasing a standard Sharp branded commercial unit that nearly every restaurant and food service place uses; they are super-tough, and much better quality than a consumer unit. Easy to wipe out, and only one control (100% power, one knob for up to 6 minutes). We haven't had a problem adapting to it - it's so much nicer, and stainless steel!