I'm sure the outcome through the T4H CR's eSATA would have been higher if we were supplied with larger drives similar to that of the WD 750GB.
Enhance Technology has given us the ability to have RAID levels achievable within the eSATA world of HDDs, in which is a cost effective alternative to SCSI setups. Having also prepared itself with multiple connection methods available makes this a very flexible external storage solution with little to no limits.
Onboard RAID cards found in motherboard devices have their draw backs; they may require more space in your case from having additional HDDs installed, and can be difficult to access HDDs in the event of failure and replacement which will have lengthy downtimes. (i.e. shutting down the PC/server to gain access and replacement). PSUs may also need an upgrade to cope with power requirements.
As for the T4H CR, it has its own independent OS and RAID controller. This baby also has its own PSU. Furthermore, it will allow you to hot swap any drives in need of replacement which is a great asset as it will not interfere with PC/server functionality, minimizing downtime as a whole.
Initiating and configuring this device is easy to comprehend for experienced users of RAID technology. On the other hand, for a novice user we found that the T4H CR is not a walk in the park. We would have liked to have seen additional features that we could benefit from such as event logging, e-mail notification and a form of GUI to obtain feedback information, as it currently would be seen to us as just an 'external enclosure' with some dandy features slapped in.
Another downside to the T4H CR is that it's possible one may easily gain unauthorized access to the menu, change settings or re-initialize the disk setup, thus causing data loss as there is no lock in place to prevent this.
Enhance Tech could look into including a key lock to prevent any undesirable users opening the door and tampering with your data.
In terms of availability, we contacted two resellers which were unable to locate the T4H CR in their inventories, thus not being able to give us a price either. However, we did some brief searching on the interweb and came across a handful of places in the U.S. that distribute some of Enhance Technology's range (including this model), and at anywhere from $900 to $1,200 USD, you'll need to be REALLY serious about your storage if you feel comfortable forking out for this puppy.