No idea who's supposed to be 'the best'.....but AB says this about theirs...and it's a lot more than the others are saying about their own Ovals
I drank some of the AB koolaid...wanna get one once I'm more sure what tooth count I'll settle into.
"Other elliptical chainrings on the market
Clocking (timing) and shape of the oval are the most crucial parts of the design. Ride quality of AbsoluteBLACK Oval ring will be different to ovals from brand X or Y.
2 years of development of our ovals resulted in commercially most successful product of its kind. AbsoluteBLACK is the First company who managed to successfully popularize ovals in mountainbike sport.
Other manufacturers offer one timing and ovality setting for all chainring sizes, but pedaling behavior changes with each size considerably. To optimize for this, every chainring size needs to be slightly different. For example the smaller the chainring size the bigger the ovality has to be to help climb steeper hills more effectively.
This is where we specialize in and optimize every size to particular pedaling style. This is also why we do not provide exact figures about timing and ovality of the chainring as each one is special and we need to protect our Patent Pending solutions. Due to our Global popularity and success there are now more companies releasing "similar" products. But "similar" is not the same. Even very small change in parameters of the oval shape and timing gives entire different feeling and performance."