Well personally i never did, no experience with it. Couldn't find anyone close to help me through it and didn't want to risk a 2-3000€ system going "nuclear" by doing things i shouldn't be doing. OCer's i talked to stated that enabling XMP rarely leads to any real performance boosts. That's done by OCing the CPU/GPU. It's been a while since i used BDRB, as it mainly only supports SOFTWARE ENCODING (yeah i used DGDecEnv but that's DECODING ONLY). My main tool now is Elaborate Bytes "CloneBD", which supports Hardware Based ENCODING as well (on top of decoding)!!! Using that and my 1080 i shrink a fully occupied BD50 down to BD25 in 9-12 MINUTES!!! Perfect x264 quality
But for 3DBD BDRB is still my go-to tool!