Looks interesting. But $718 for an additional 180cc of air...? Pass.
You're partly right. But there's more to it than just another 180 cc of air. I see it as an extension
1. 180cc of air
2. Bag rider
3. The possibility of easy installation of a monopod
4. Bottle protection
5. Preservation of all stock adjustability
6. Potential for further expansion.
When I consider what other stock manufacturers bring to the table, it's always
1. The elimination of the entire bottle in the rear
2. The need to mount the bottle in the front of the gun
3. The original Arca Swiss rail is also lost when I move it to the front.
4. Negative weight transfer to the front of the gun for hunters.
So in conclusion, I think that using this stock even though it is more expensive in a way, it might just give the hunter more shots in more power and more weight to the body and thus better stability when shooting.
So too for people who maybe shoot PRS competitions where it will also give them more shots and overall stability.
And that's certainly not the whole list of possibilities.
PS: I have already ordered it for the reasons I see in it. I'm a long range shooter and I use a similar setup as they have in the photo because it's important for me to have as much air as possible right on the airgun so I don't have to carry a big air bottle with me.