Re: "Proper" reviews
It bothered me, so I looked them all up - used the Reg review as primary source, then manufacturer figures, then other review sites if there was still no figures published)
1) Buffalo Linkstation - 24W max (src: http://www.reghardware.com/2011/01/20/review_storage_buffalo_linkstation_pro_duo_nas/)
2) Buffalo Terastation - 47W max (src: http://www.buffalo-technology.com/en/terastation-pro-duo.html)
3) Freecom Silverstore2 - 24W (src: http://www.freecom.com/Products/External-Hard-Drives/Network-Hard-Drives/SilverStore2)
4) Freecom DualDrive - 16W (src: http://www.expertreviews.co.uk/network-storage/1283860/freecom-dual-drive-network-center-2tb/specifications)
5) NetGear ReadyNas Duo v2 - 60W (src: http://www.reghardware.com/2012/01/18/review_netgear_readynas_duo_v2_network_attached_storage/page2.html)
6) QNAP TS-219P II - 23W (src: http://www.expertreviews.co.uk/network-storage/1291528/qnap-turbonas-ts-219p-ii/specifications)
7) Synology Diskstation DS212J - 17.6W (src: http://www.synology.com/products/spec.php?product_name=DS212j&lang=enu#p_submenu)
8) Synology Diskstation DS212+ - 18.7W (src: http://www.synology.com/products/spec.php?product_name=DS212%2B&lang=enu#p_submenu)
9) Thecus N2200EVO - 52W (src: http://nas.findthebest.com/l/748482/Thecus-N2200EVO)
10) Western Digital My Book Live Duo - 15W (src: http://www.expertreviews.co.uk/network-storage/1291513/western-digital-my-book-live-duo-4tb/specifications)