Pros: The the SansDigital Mobilestor MS2UTN+(B)is a well-designed and solidly-built enclosure. The power is internal and eliminates the clutter of another power brick. The two WD 750Gb Caviar Black drives installed easily onto the sliding supports which fit perfectly into the enclosure. I configured the "Storage Design" as a 500Gb SAFE (mirrored RAID 1) and the remaining 196Gb on each drive as a BIG 396Gb drive. The guide for doing this is provided on the software for the GUI interface which must be downloaded from SansDigital's web site. The building of the SAFE mirror on the second drive took several hours. The drives are kept cool and the enclosure is not warm. Note: If you change the configuration switch, you must then press the reset switch with the power on. The controller with take over and configure the RAID or allow GUI interface.

Cons: The instructions are minimal; mechanically you could figure out how to install the drives on your own. They are useful in interpreting the red and blue activity lights and in recommending that new, identical drives be used. The fan is noticeable. The slotted configuration selector switch is recessed and ambiguous. The ambiguity can be removed by noting that the original setting is "0" and using a Sharpie marker to mark the selector. Note: You cannot access more than one physical or virtual drives with eSATA unless your eSATA host is port multiplier aware.

Overall Review: This is my first experience with RAID and I had to do some research. This uses the SteelVine Silicon Image SiL5744 RAID controller. In addition to the switch selectable configurations you can set SAFExx with BIG or FAST for the remaining space using a GUI interface. A guide for the SteelVine 57XX family is contained in the downloadable package available from SansDigital. Read it first to Chap. 5 before doing anythin. Find it under the C:\Program Files\Silicon Image\57xx SteelVine for SteelVineManagerHelp.pdf after software install. Note that some other reviewers suggested that the drives be formatted prior to setting a RAID configuration. Don't; you format after the two virtual disks have been configured by switch selection or GUI. Exception is the JBOD configuration when you are just using the enclosure to house one or two independent disks. Use Windows Disk Management to initialize, partition (format) the resulting RAID drives. Note: You cannot access more than one physical or virtu