@sharkattack – an oval ring will help “circle the square” of your pedalling and (supposedly) improve traction which is what AB sell them on. As rone says, they don’t seem to work when stood up, that’s probably due to the lack of bending at the knee compared to seated pedalling.
I fitted one to my hardtail – it was sufficiently different and for me, better, that when I built up the fat bike I effectively forced myself into a corner as I wanted a 28T oval ring so had to go direct mount which limited my crank options. For a fat bike, especially in sand/snow they are ideal as you tend to ride seated and you don’t get that variation in traction/pressure that causes the surface to give way.
If you get one and don’t “get the lurve” then you’ve always got a spare chainring just in case to cover you should your circular one need replacing in a hurry.