There are a number of websites where you can find independent reviews of Siddons heat pump water heaters and those of other manufacturers, as per the links below:
Product Review is Australia’s first and most comprehensive consumer opinion site, online since May 2003. We provide a platform where people can rate and review products and services and the shops that sell them. It is consumer response – satisfied or not!
CHOICE was founded in 1960 with one clear mission: to ensure the consumer voice is heard loudly and clearly. CHOICE empowers consumers to get the most out of all their purchasing decisions by providing a mix of advocacy and advice.
Whirlpool is an Aussie discussion forum, founded in 98 by Simon Wright. It expanded rapidly and substantially since that date, with over 400,000 members at the present time. The intention of the Whirlpool Forums is to offer a venue for debating technology, networking, broadband and other similar topics.