Shunyata or Synergistic for power conditioning?

Hamburger, I have the feeling that you are going to have to find a dealer that carries both brands and listen for yourself and/or have them describe what they hear, and the differences.

lak is correct. That's the only way to do it. If you live in the US, call The Cable Company. They can send you demo's of both units. 

Sorry I cannot comment on the comparison but I own the 12UEF and could not be more pleased. However the Denali is also a very well reviewed unit and one I would be happy to own. Based solely on ease of use and my beliefs on synergy my advice would be that if you already have a lot of SR kit then go with the 12UEF but otherwise choose the Denali, if only for the plug supports which are a godsend, and something I have to improvise on my 12 UEF. One material consideration is that the Denalis do not come with a power cord, that actually makes them much more expensive if you do not have a spare suitable cord (in the $2-3K range) handy. Hope this helps. You can find my experience with the 12UEF here

Thank you guys!
The problem is that both products are sold by different retailers and both do not have the products for home trial.

That aside, I appreciate the kind advice from folkfreak from a "holistic" angle of owning a particular product. I own neither SR nor Shunyata products currently. I think SR has more products in their arsenal (Tranquility, grounding, etc)...

My cables are all HiDiamond.  Will the HD3 power cord from wall to Denali work well, I wonder.