Hi Tiago,
Tough competition there. All three devices are really nice but I personally like CMA800i the most. If pure detail retrieval is your thing and you want absolute maximum inner detail, the Hugo might be the best choice. CMA800i is only behind by a hair though and has a more organic, well balanced sound overall. DA8 II trails them both in detail and is generally a different sound - thicker, warmer, though not overly so, it isn't as lit up in the treble region.
With HD800 I do think the CMA800R is an improvement over the CMA800i. Not massive by any means though. Only spotted during critical listening. We're talking well beyond the point of diminishing returns at this stage.
CMA800R is more detailed than Taurus, no matter how you run Taurus. The AURALiC model is warmer and somewhat smoother overall. More relaxed listening while CMA800R is more upright, full attention, active listening.
So, depending on what you want, it's still a tough choice. Sorry!