Three years later and Zen now has the DP-100-ACR (with Removable shade). The mount is the same and does not allow the port to be locked.
The Zen port is a cheaper alternative to the Aquatica when using just the Canon 8-15mm Lens.
2016 Retail Price
Zen Port US$899 (extension not needed)
Aquatica Port US$734 + Extension US$249 = US$983