I know it's anecdata, but in my brand new Bosch dishwasher the "EU" mode is clearly the selected by default ECO mode - and yeah, it takes 3.5 hours, but it uses about 1kWh of energy and only 9 litres of water. And I have never, not even once, had it not clean something perfectly. And I've been using it on burnt oven trays and dishes stained with egg or cheese based meals - it's perfect every time. If I do need dishes back quickly, then I just press "VarioSpeed" and the same program is done in an hour - with the same results.

It must be a quality thing I guess? Cheaper/worse dishwasher will never clean dishes as well as a better one without using least efficient programs.

And what's wrong with vacuums? I got the good old Henry hoover(if you're in UK you might know the brand) just a year ago and it's as good as ever.