This is a 24 inch combo on a pedestal, so smaller then a duet.
It has a 2.3 cuft drum. That is 65 liters.
In the EU, the rule of thumb is 1:10 for washing (1kg of laundry needs 10 liter of drum volume) and 1:20 for drying (1kg of laundry needs 20 liters of drum volume to dry quickly and without major creasing). These sizes allow for propper and quick tumbling and thus cleaning/drying, though one has to say that usually the ratios can be a little lower, especially if we handle loads like towels which aren't at a risk of creasing.
That would mean 6,5kg of laundry for washing and about 3,5kg for drying according to this rule. In pounds, that would be about 13 pounds for washing and 7 for drying.
Now, last time I checked my size M T-Shirts were about 200-300g a piece, so 2 would be about a pound. That would mean I could wash and dry 14 T-Shirts in one load. Or 10 T-Shirts and about 7 sets of underwear (underpants and socks).
A usual pair of jeans is somewhere in the realm of 1-2 pounds. Same for sweaters, maybe a little less for sweat pants and such. So I could wash and dry 3 pairs of these, maybe even 4, with little creasing.
Towels weigh about 500-800g per square meter. So, a normal hand towel (ours here are about 50*100cm, half a square meter, or 20*40 inch) would weigh about 400g, or lets say a pound. Our big bath towels are 80*40 inch, so 4 times that, about 3 pounds. My bathrobe is 4 pounds. So I could wash my weeks worth of towels as a single (2 hand towels, bathrobe, big towel, 2 dish towels) and dry them in one go.
As couple, you could say you have 4 T-Shirts a day, 4 sets of underwear, and some other mixed items. So a load every 2 days would cover that.
Every other day you change jeans, sweaters, hoodies, such.
And towels twice a weak.
And that is given you do one load a day. That thing is 240V, it should to a load in less then 3, closer to 2 hours. So 2 loads a day are verry well thinkable. So you could even be less conservative about the clothing estimate of a young urban couple.
Sure, more then 2 people and it gets tight, but it sure is a concept that works fine.
The only issue I see is having a 240V connection in place. However, in newly constructed or remodeled situations, that could be managed as well, given that any flat needs either gas or 240V for a range in the kitchen.
So, it sure is not a combo for every one, but it's a good combo never the less.
