These are simple plastic cages. They are reasonably lightweight and look good. They grab the bottle snugly and that's good if you're using these for MTB, riding gravel or on bumpy roads. You can spend a lot more on a bottle cage but you won't get any better functionality than these provide. The snug fit could be an issue if you are challenged at quick bottle removal and replacement but it's not a big deal.
Holds bottles very securely. However, if you're using Camelbak Podium bottles, they can be difficult to get in and out of the cages because of their shape. Stick with straight-sided bottles for best results.
I know it's not as fancy as some of the carbon cages out there, but it's still super light and I've never lost a bottle. The price is right too, and if it's good enough for the pros it's good enough for me.