Rating: 4 / 5
My review would be between the 3 and 4 ratings above. I give it a 4 because it does a few things well: (1) it is as light as advertised and (2) it protects the rod from the major problems like branches catching an end of the rod and breaking it off or catching a guide, etc. and (3) fits well in my pack side pockets.
I agree that is a little flimsy. In fact, I was a little disappointed when I first opened it and realized that it is not stiff enough not to bend fairly easily. However, after putting my flyrod in there, I noticed that it no longer bends as easily and actually protected the rod from bending. I put an old flyrod in there and try to catch it on a branch while walking, it wouldn't bend near as much as just the rod by itself. And the tube prevents the branch from catching one of the lighter parts of the rod, like the tip.
I'm not saying I'd put my bamboo rod in it and go treking down the trail, but short of a titanium rod case, I think it works adequately. I would give it a 5, but I am left wondering if there is something else out there that might be better, as the posters above said.