Technically, the drive can be reformatted to work with Windows, and the included LaCie Private Public, a security utility that keep the information on the drive secure in case of theft or loss, is available for both Mac and Windows computers. There are more Macs that support Thunderbolt on the market than there are Windows computers, however.
The LaCie Little Big Disk Thunderbolt 2 worked very well in my testing. The drive takes just a second to mount once it's plugged in, and it shares its power status with the host computer. It turns off when the computer is shut down or put into sleep mode and then turns back on when the computer wakes up. Each time there's a change in power status, the drive responds instantly -- there's no waiting for it to be ready.
I tested the LaCie with a late 2013 model MacBook Pro, which supports Thunderbolt 2 and uses a fast PCI-express solid-state drive as its main storage, and the LaCie blew me away. In the default RAID 0 setting, the drive registered a sustained write speed of 568Mbps and a read speed of 643Mbps. When I made it work on its own, doing both writing and reading within itself, it averaged more than 500Mbps.
This means the first set of numbers shown here is likely the speed of the test machine's internal drive. If I had a test machine with a faster internal drive, chances are the Lacie would register a sustained speed of more than 1,000Mbps. To put this in perspective, with this kind of speed, you can put a CD's worth of data (some 700MB) on the drive in significantly less than a second.
When I switched the internal SSDs into RAID 1, the performance was reduced but still very impressive, at 452Mbps for writing and 557Mbps reading. Never before have I seen an external storage device this fast.
The LaCie also remained quiet and cool during the testing. I didn't hear any sound coming from it at all.
The LaCie Little Big Disk Thunderbolt 2 clearly shows off the superiority of the Thunderbolt 2 connection: its only major shortcoming is that it's cost prohibitive. With a price tag this hefty and a capacity cap of just 1TB, the drive is obviously a niche product for those willing to pay a high premium for top performance. That said, if you have the need and the funds to invest in a Mac Pro, you'll find this new external storage device very tempting, to say the least. And when you do buy one, just the performance alone is enough to justify your decision.
On the other hand, if you don't have one of the latest computers that supports Thunderbolt 2, this drive is probably not for you, since you won't be able to realize the performance it has to offer. In this case, I'd recommend theor the instead.