I already paid $100 more for 2dB less, according to the spec. No regrets.
> which I believe is required by some regulation to be the default
Huh. This must be recent-ish. My parents' dishwasher has a rotary button to choose the program, which stays put as long as the little grandchildren don't mess with it..
> From 1 March 2021, household dishwashers shall provide an eco programme meeting the following requirements:
> (a) this programme shall be: [...] set as the default programme for household dishwashers equipped with automatic programme selection or any function maintaining the selection of a programme, or, if there is no automatic programme selection, available for direct selection without the need for any other selection such as a specific temperature or load;
Ours was bought in late 2020, but manufacturers probably take a head start with implementation whenever they renew their models.