It has been wonky since I purchased it. It have difficulty mounting SSDs from the beginning and now wont power up. I would avoid this. Contacted OWC customer service and they require me to pay for shipping. Not good.

The unit malfunctioned after the 2nd day of use. MacOS keeps reporting the disk has not been ejected properly even though the computer is sitting idle (not being used). Sometimes several 'disk has not been ejected properly' messages are on the screen after the screen saver kicks off. Computer is set to never sleep the computer (Mac Mini) and turn the display off after 1 hour. In addition, second Thunderbolt port will not work with LG Thunderbolt monitor. No display. Have to use HDMI port. Will return the unit.

The build quality is very good on this dock in fact exceptional. However I do have one issue, and th reason for 4 stars and not 5, is that when I am transferring large file to a drive in the dock, as the file is moved the speed seems to slow down becoming almost agonizing slow at the end. Now my Thunderbolt 1 dock hooked to my Thunderbolt 2 port never had this issue, it just steadily moves until completed. I have not actually measured this throughput but a file moved to the Thunderbolt 2 dock takes longer than when hooked to my Thunderbolt 1 dock with the same drive on the same computer with Thunderbolt 2 ports. I find that a bit odd.

However the convenience of being able to shutdown my drives as opposed to them always running in my TB1 is fantastic. Also there is no power brick on the outside as on my TB 1. All pluses in my book.

Price wise they are high even on sale, but it so far has worked for me well except for above.

I find these well worth purchasing if you have the money.

Very happy with it. I work off a SSD in one slot and back it up to a 3.5 HDD in the second slot. Fast and reliable. Works as advertised.

Good looking, but not that fast. I only got 180mb/s, not 680mb/s.

Although my macbook has pretty advanced hardwares. I'm still gonna to find out the problem.