I am currently redesigning my kitchen in a 1930's Midwestern USA house. The kitchen has a decent floor area but the floor plan is oddly restrictive.
My space next to the sink is such that I can either have a standard 24" dishwasher next to the sink and a slightly weird cabinet adjacent to it, or I could have an 18 inch dishwasher at 45 degrees flanked by two small but reasonably sized cabinet doors (or drawers), although the 45 degree plan would dictate a somewhat shallow custom counter depth on the flanks (like 18-20 inches).
I think I would be more proud of the accomplishment of building the angled design, and I think the ergonomics would be optimal.
But I'm not sure about the smaller dishwasher. I have never used a smaller one. It seems like it would be enough for my small family and still plenty helpful for gatherings.
We were almost literally in the exact same scenario and era of home. We went with an 18", our first dishwasher in 8 years.
My girlfriend and I cook a LOT, so we make way too many dishes. On a bad day I fill up the dishwasher before my sink is empty and have to hand wash a few extra plates. I usually avoid putting pots and pans in there, honestly it doesn't fit well with much else in the bottom row if you have that utensil thing in place.
If you only use a couple plates and a mug or two a day, its really easy to just put it in the dishwasher Instead of the sink and when full just hit CLEAN.
Was it worth it.... I guess? How much do you hate dishes. Anything more than 2 people probably go bigger.