Pros: Inexpensive enclosure that works well for RAID 1 redundant storage.
eSATA interface allows for higher transfer speeds than USB 2.0
Cons: The actual SMART data of the drives is masked from the host, while the enclosure provides non-standard SMART data (unknown attributes) with "failing" values.
This causes Linux to flag the drive as "being used outside design parameters" even though there is no problem. The only way to stop this is to disable SMART monitoring of the RAID.
As a result, no software monitoring is possible, and you have to rely solely on the "Alert" LED on the enclosure to know if anything is wrong.
Worse yet, it isn't clear from the poor documentation if this LED indicates only RAID errors or if it will also alert for drive SMART errors.
Additionally, attempts to use this enclosure for RAID 0's performance boost fail. Instead of almost doubling throughput, it ends up a bit less than the performance of one drive alone.
Add to this fan that is loud even in its low speed. So you aren't likely to have this sitting on your desk, making it unlikely that you'll see the "Alert" LED if it does illu
Other Thoughts: Despite all of the shortcomings of this enclosure, this enclosure is one of the less expensive ways to set up redundant storage.
However, if you can afford the extra cost, I would recommend looking into a "smart" NAS enclosure instead.