I've logged over 5,000 singletrack miles the last few seasons using an elliptical ring and have yet to drop a chain. I'm a huge fan of the rings in this application, but admittedly most of those miles have been on a Rotor setup - crank & ring combo. It was flawless.
So when I recently got a new whip, and my Rotor crank wouldn't fit, I was pretty bummed, and had to look for a new solution. Absolute Black nailed it, and after a couple hundred miles, I'm all smiles, and likewise have yet to drop a chain.
In all fairness, the pedaling has slightly more feedback on this ring than I had experienced with the Rotor -- it's not enough of an issue to reconsider my build, but worth mentioning.