QNAP has a veritable cornucopia and can cover any needs. Not only at home but also in a larger office or medium-sized enterprise. It's the performer in fantastic price. In the category of the best Performance Per Watt, QNAP is an undisputed king in the market. If you do not need so much, or afford to invest so much money into a NAS, it has also QNAP TS-239 Pro and 439 Pro, which takes 2 and 4 discs. Concerning features and performance into consideration, so there is no equivalent in the market. ReadyNAS, Synology and other manufacturers of small NAS units were the best of my opinion, but not up to QNAP TS-639 in Pro's league. It will have a very warm recommendation from here.