I've been using a Specialized Rib Cage and found it the perfect combination of never losing a full 1l bottle and being able to get the bottle in and out when I want to. The stretchy rubber band seems to work far better than a metal loop.
The only problem is that it has got a flat mounting surface.
My new frame has got raised bottle bosses, they are actually rivnuts.
This means the cage is raised slightly away from the frame with only a very small contact area, the heads of the rivnuts. I can't see it lasting long with a 1l bottle in it.
I could do with a bottle cage with a curved mounting face to match the frame and recesses where the bosses are so it sits down snug.
It's also got to never lose a bottle. There must be a lot of cages that don't grip very well, judging by the number of bottles I see on the floor at marathons.
It must be easy to get the bottle in and out while riding too. I don't get on with those side loading ones.

Any recommendations ?