Power Conditioning, Torus, Audience or David Gray?

I haven't tried all the brands you list, but I can tell you that the AR1p dramatically improved my system in terms of noise floor, separation and overall clarity. I'm using one at the end of a Wiremold strip. I've tried 2 PS strips in the past and found they both negatively impacted the sound, IMO.

Keep in mind that the effect any power conditioner will have is highly dependent on the initial quality of the power in your home, as well as the ability of your components to deal with the AC as it comes from the wall. As with any component, it's a matter of system compatibility and I don't think you can generalize that something is "good" or "bad". There are several AR1p's for sale at reasonable prices on A'gon and I think it's worth trying. You won't take much of a loss if you decide to sell.

Most of the reviews I have read for the Ar1p have been with it in line with another conditioner and the reviewer liked it. Price point makes sense. I have been toying with the idea of running a dedicated 20A outlet from the panel box with hospital grade outlet. Glad to hear from someone who has tried the Ar1p instead of a paid reviewer.

By all means: run the dedicated line(heaviest possible gauge) to your listening room. The Richard Grey products are actual power purifiers and not fancy power strips which can and will cause sonic anomalies. Everyone's AC has noise generated by everything else online from the power station to their outlet. The improvements are more what's missing(noise/hash/grunge) than anything that added. They just allow more of what was always there to be appreciated(via a "blacker background"). I would spring for the extra $$ and go with the RGPC products. Have you plans to upgrade your power cords too? Noticable benefit can be gained there as well.

The Audience AR1p is a GREAT product, and not "just for the price," but ESPECIALLY considering the price. I've had several of the "Big Boys" including Shunyata, PS Audio, Tice. The Audience was the FIRST one where I didn't have to strain to hear it. I was reluctant to purchase it, but thought, what the h***, it's only $500. I find it is easier if you play POOR recordings, and not the good ones, because you don't need to strain when a poor recording shows improvement, whereas with the better ones, you say, "oh yeah, I hear more harmonics, and I can hear inner detail on the flute," etc.
The Audience seems to remove grain in the same way that older Avalon designs remove it: not just the proverbial "blacker background" which is easier than implied here (just try some Versalab rollerblocks on one pair of interconnects), but a sense of "continousness": the feeling that all the instruments are in a living, BREATHING, space all at the same time. No "materialization" of one section, such as violins, and then a disappearace as the brass or cellos come in. Nope, the space sounds alive, as in Saturday broadcasts from the Metropolitan Opera, and, for those who haven't heard it on a decent system, this is the difference between hi fi and real life. Once you hear a broadcast from the Met, you understand the concept of continuousness. One feels the air on the stage and the slightest low-level sound consistently "floating" out of your speakers. The AR1p is admirable at recreating that sensation. Even if you have merely an "okay" system, you will hear it. (I'm using ASL's cheap little 30-watt class A integrated, and it's no great shakes at low level detail, trust me. But tonight, for the first time, playing a poor recording of Peer Gynt, I could hear floor sounds, sounds outside the hall. I looked like a dog cocking his head to the side when he sees/hears something odd.)
If you have a good system, you'll doubt your ears -- for a few minutes. Trust me, this isn't hype. Besides, Audience gives you 30 days to try it out, and I tell you that as a new customer. I've had mine for 3 days, and I'm keeping it. Try it!