Ken Rockwell says that it is the fastest SD card reader he has tested:
I imported to Photos today, and it imported so fast, I did not realize it had happened!
I like it as a general dock, too. It has all the connections I need.
Note that while those ports do offer high-speeds, it will depend upon the "data chain" (throughput is constrained by the slowest device/connection in the chain).
e.g. I use the built-in UHS-II card slot in my iMac Pro to read such cards. The main data drive (a RAID 10) is connected to the iMac Pro via Thunderbolt 3. Even though Thunderbolt itself is rated to 5 GBps (40 Gbps), that RAID 10 unit maxes out at 600 MBps writes. But, the Angelbird UHS-II V90 cards max out at 300 MBps reads. So the SD cards in this case are the bottleneck.
I also have an external RAID 0 attached to the same Thunderbolt 3 chain. It has built-in card readers for both Compact Flash and UHS-I SD. The cards again (read speeds) remain the bottleneck.