Hybrid SACD are they compatible w/non SACD playe

Hybrid SACD's have two formats, SACD and RBCD. These hybrid CD's will play on either type of player. SACD CDP's will usually default to SACD layer, but on some at least on my Marantz you can also select RBCD layer instead of the SACD layer. The hybrids should play on any CDP - that was the point in making them hybrids.

Re differences in sound I assume you mean an ordinary redbook CD and the same performance on hybrid disc played back on a redbook player. I've never pinned down a difference in sound quality. The obverse is not necessarily so on my Marantz SA11s3. It has excellent dynamics, more so than my other CDP's, and it seems that ordinary redbook CD's take on that quality, but I don't think this is anything inherent in the CD itself.

FWIW.

The Hybrid SACD's are 2 layers. One for CD and the other SACD. Playing it in your ARC will access the CD layer. It should sound no different than a regular CD. If you do think it sounds better, its probably because your ARC is a better sounding component than your SACD player. Just because SACD is a better format doesn't mean that it will automatically sound better than any CD player. To get the best out of SACD's, you'll need to get a high end component, just like you would for any other component.

I think that is the biggest reason why people who try SACD, aren't that impressed with it. Myself included. I went out and bought a Sony DVD/SACD player and was a little disappointed with the results.