No experience in a 5th gen, Fox or with an OME BP. I'd actually recommend the 2.5" Kings, Fox or Bilstein's over anything else because well, they win races. I have Icons w/ CVDC in my 4th Gen and it's currently a bit heavier than a 5th gen and the ride stays nice and plush on long & higher speed trails (35-45mph). My friend has Kings with reservoirs on his GX470 and is also currently heavier than the 5th gen and rides similar at those speeds. The Kings do have a bit softer ride on slower trails.
The standard OMEs are great - low cost, durable and decent ride. However, the OME BP-51s are way too over priced for a 2" damper, can't rebuild or tune them and they need to be removed to adjust the preload.
You can watch this video that goes into the OME-BP51 at the 12:00 mark.
https://youtu.be/-MsKf1lIYI0