yep, productreview is a great website when buying things...we have an LG DirectDrive, very happy with it, got a good deal from the Good Guys, if you have one close to you.
I am not sure whether it's better to have one which directly uses your hot water system or not.
However in Qld, we have had an unusual electricity night tariff for 8 hours overnight - tariff 31 which is very cheap. My parents thought they would get a 315L hot water system, after both of us kids moved out. Well they have too much hot water so their dishwasher runs straight off the hot water system.
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