I have a BlackJacket for 5X7 and I really like it for both of my cameras. The BTZS hood, by contrast, compersses and distorts the bellows. The ability to adjust the tensin of the hood around the camera is a big plus for the BlackJacket over the BTZS in my opoinion, at least with these cameras, an old Nagaoka and a Canham MQC.
On the other hand, the BTZS hood for 7X17 works nicely on the Canham. I don't have a BlackJacket in this size, though I have tested a a prototype which looked promising but still had a way to go.
Sandy King