Richard Gray 400 ?

What is the difference between the original 400s and the newer 400 MKII ? Do they look the same? Do they sound the same ?
It sounded restrained and heavy filtered. It took the life out of the music. I was better off using the AC wall outlet. On the other hand, I've tried some other conditioners and they work much better than the AC wall outlet.
I wish I could tell you the difference between the 400S and the 400 MkII, but I just do not know. I will say though, that my experience with my 400 MkII has been exactly opposite that described by S23chang. For me the music came alive, with increased dynamics and better clarity, and that was with just one 400 MkII!
I guess the manufacture might have fixed the issue in MKII version.

Maybe nothing was fixed. I've seen mixed results with the Richard Gray power conditioners, so it may just be how it interacted with your equipment. My results though, were spectacular. So much so, that I have added several more of their products to my system since that first 400 MkII.
I don't know Slv... I thought was just my setup so I brought over to other friend's house in their setup and got same result. The guy who sold me the Richard Grey also told me the same thing after I bought it. He uses Audio Prism conditioner now and I use Hopsital grade conditioner know and they all much better than the Richard Grey. I also had PS Audio 300 and it was better than Richard Grey too. So I don't think something didn't work well after 4 different setups would be spectacular.
Btw, all the above conditioners cost more than twice of the Richard Grey.
My experience is the same as Slv's; I've now got one on each of three dedicated lines. An important caveat, though, is that it sounded exactly like S23chang described when I first inserted it into the system. My dealer warned me, and he was right, that you have to give it about three days to run in (get the transformer saturated, I don't know?) before listening to it seriously. Then it will perform at its best.
I have the RGPC 400S Mk1 & had an email comm w/ RG's co. re. the changes to the Mk2. What I learnt was that electrically nothing had changed. There are some cosmetic changes like an on LED & the better ability to rack mount.
I have the RGPC 400S Mk1 on my front-end components only & I can say confidently that the sound is *not* degraded. Is it improved? Maybe but, importantly for me, it's not degraded. I will never use it for my preamp nor my power amp!
Power conditions are so very subjective & there has been much heated debate on this topic so I'm not surprised to see replies on either extreme!!
Rcprince - You're right about the break-in required for these products. I had forgotten about it when I responded to S23chang.

S23chang - Is it possible that you didn't leave the 400S in your system long enough to realize it's benefits? Just wondering.
I had it for a week and I was fed up.