The 230 V inline pump has been deprecated, and the recommended solution is now the 12 V inline pump, 256825. It is quieter than the 230 V inline pump, has variable speed, allowing it to be used for purging air, and can run from the 12 V leisure battery if off-grid. The motor is the same make as the 230 V. And it's cheaper.
In short, there are only advantages to using the 12 V inline pump over the 230 V inline pump. (As an illustration, Airstream USA stopped using the 230 V inline pump in 2014, using the 12 V inline pump instead.)