Size matters.
2 points:
1. Look at the efficiency for the size. How much energy is consumed per cubic foot to keep it at X temperature?
2. This is possibly more important than the first point. How much refrigerated space does one really need? Would you save money using a smaller, but less efficient, refrigerator if you didn't need that much cubic footage?
Right now, Elginkid and I live under the same roof and share about a 1950 Frigidaire. It' pretty big for its day (although the shoebox freezer is nearly worthless). It doesn't draw much power, it performs quite well, it is extremely quiet, and we can fit everything we need inside it. Living with a smaller fridge has necessitated some lifestyle changes, but it has been a mostly good experience. I waste less food now because there is less space to loose things and forget about them until after they spoil. We have fresh food all the time because we can't warehouse lots of food in the fridge for weeks on end. The butter is spreadable because we keep it in a closed butter dish on the counter next to the refrigerator. Butter really doesn't have to be refrigerated if you use it within a week or so.
The benefits for us include: lower overall power consumption, fresher food (the expense of having to buy food more frequently and in smaller quantities is offset by the reduction in waste), and having a really cool looking fridge in the kitchen.
The disadvantages include: monthly freezer defrosting, little usable freezer space, not so good at making ice cubes. The last 2 items can be rectified by getting a small freezer and putting it in the butler's pantry.
Overall, we love our old fridge. Also, consider how much waste is saved by keeping an appliance for 60 years as opposed to replacement every 5-7.
Dave