The BacPac is just what's needed for GoPro users like me who need accurate framing and exposure (the GoPro has automatic exposure, so the amount of sky or backlight in the picture has a profound effect on how dark or light your picture is).
Using the menu is simplified as the LCD allows more space for explanations of menu changes (excellent). The BacPac allows you to play back your footage, too.
The only drawback as far as I am concerned is that the LCD and see-through back of the waterproof housing, are both very easily marked. Despite the fact that there are four housing backs with the BacPac - two for wrist mounted units and two normal (waterproof and non-waterproof for better audio) I anticipate needing to buy new ones (if available) quite soon.
Now that we can see what's going on with the GoPro, I hope the manufacturers will give us two stops (each way) of exposure compensation for the GoPro, so that we can get even better pictures with this fantastic little camera!