I've been researching the prices for NAS lately. The Netgear 4-bay looks pretty affordable compared to WD My Cloud EXT-4 ($449) and is more well-known than PROMISE ($249). Not too sure how they compare performance-wise.
Specifications:
CPU MarvellĀ® Armada 370 1.2GHz
Memory 512MB
Drive Bays 4
Drive Types Supported SATA/SSD 2.5? or 3.5?
Hot Swappable Drives Yes
Tool-less 3.5? Disk Installation Yes
eSATA Expansion Ports 1
Total Solution Capacity Internal 16Tb
Gigabit LAN Ports 2
USB Ports One (1) USB 2.0, Two (2) USB 3.0
Power Supply 12V, 7A External 90W; input 100-240V AC, 50-60Hz
Power Consumption: Operation 45.6 W
Power Consumption (Wake on LAN) 1.4W
Power Consumption: Power Off 440mW
2-Line LCD Display Yes
Here is a comparison of the Netgear NAS products:
http://images.anandtech.com/doci/5071/nv_02.png
All the items included in the sale:
Netgear ReadyNAS 2-Bay/4-Bay Marvell/4-Bay Intel $147/$248/$455
Seagate NAS 2TB/3TB/4TB $116/$148/$209
LiteON eHBU212 USB 3.0 External Blu-ray Burner $89
Rather a HP Microserver at that price.