I had to go to the LaCie website to get basic specs for these drives, would appreciate if MacRumors would include them in future:
- the Mirror drive is USB 3.0 only. I agree that it's expensive for what it is, but hey, for those who can afford it and want stylish products, I can see the appeal.
- the 4TB Rugged RAID Thunderbolt hard drive is USB 3.0 and Thunderbolt-1. I can also see the appeal for a portable high capacity drive with RAID, for some users.
The point made earlier regarding the disc speed (5400 rpm, which is not in the specs on the LaCie website) is a good one. I purchased one of the LaCie Thunderbolt 2 desktop hard drives (7200 RPM) just a few months ago, to use with my new iMac Retina, and went with the Thunderbolt 2 since the iMac also has that capability. At the time I didn't realize that the disc speed would in fact limit the data transfer rates. Those desktop drives do have an SSD upgrade available, which would possibly remove that limitation (or minimize it), but it is an expensive upgrade.
Bottom line from my point of view is that until we have these products available with SSD hard drives, the data rates will not generally be achieved in real life. And there is no gain to be achieved from Thunderbolt 2, as far as I can see, unless you have an SSD drive at both ends.