CMMG pioneered the radial delay blowback. To my knowledge they only use it as a replacement for direct blow back in pistol cartridges to mimic the performance of a gas system. Mostly likely due to the lower pressure/gas volume of pistol cartridges. They don't offer it in rifle cartridges which is somewhat telling on its own. My guess it that it is less reliable than direct impingement
Roller delayed blowbacks aren't known for being particularly pleasant to shoot in rifle form. Not bad, but not as smooth as a gas impingement system like an AR. Their accuracy I believe is about the same, not bad but not great typically. As far as tuning them, you have to contend with bolt gap which is adjusted by roller size. Get it wrong and the rollers will actually bulge the receiver at the rear of the bolt's travel. They are known for being rough on brass, so its not something you would want to reload for if you intend to reuse brass. There is a reason this system isn't really produced by anyone anymore and everyone likes to copy the AR-18/180.