I have not tried the Caldigit, but I got the Belkin thunderbolt 2 dock. I'm not very impressed with this whatsoever.
Pros
Design is compact, and looks sleek, has single usb3 on the front, thus can hide the remaining ports on the back.
Has Ethernet, hdmi and headphones on the rear, which allows one to hide the cables behind my iMac
Cons,
-USB3 is limited. I tried a Samsung evo via a usb3 dock which gives me 410mbs write 450 read, when connected to the dock, the reads go down to 350, and the writes, a measly 280 Mbps/s. I tired this with a different usb3 enclosure and noticed that for ssds, the belkin dock is markedly slower than native usb3 or my £15 usb3 hub.
- Not truly hot swappable: when unmounting drives, if one tries to reconnect the drive, whether an external hdd, ssd, sub thumb drive, I need to restart the iMac. This issue using the same peripherals via my cheap usb3 dock.
-Ethernet does not flawlessly work, it sometimes hangs me use, and refuses to connect after waking from sleep. I tried this on my mbp also and noticed this issue.
-Daisy chaining my dell monitor from the hub works well, apart from instances of freezing after waking from sleep.
Given the obscene cost of the dock, I have decided to rerun the item instead.