Hi Rob,
Re: Synergistic, I have several generations of their power cords, from the original Master Coupler to four gens of their "active shielding" series power cords ("X", "X2", Tesla, and Element CTS) and their Tesla Apex XLR ICs and Precision Reference speaker cables. I find their active shielding products to be magical at "blowing out the walls" of the listening room (allowing massive perceived space limited only by the recording), especially after having fellow-member Michael Spallone perform his inexpensive MPC mod.
The "SE" versions of the Tesla and the entire Element series have interchangeable tuning modules for each cable/cord that I find very useful in tweaking the upper frequencies to get maximum open-ness and air and eliminate glare and stridency. Those are the sweet spot for me and can be bought used at reasonable (to me) prices.
I have not tried SR’s latest Atmosphere line.
My Transparent Audio cables are their Reference XL XLR IC’s between my DAC and preamp in my computer-audio front end. Very good cables; balanced, well-integrated and musical with excellent open-ness and detail. Very expensive and TA is constantly offering owners "upgrades" that I find to be unreasonably priced considering the initial cost of the cables.
I strongly recommend that you hear any cables in your system and in your room before buying (or with a return provision) vs hearing in a dealer showroom setting with unfamiliar equipment and room, thus my earlier caution.
Hope this helps Rob,
Dave