Modded SACD player: SACD or Redbook sound best?"


I have a modded SACD player (Sony 9000ES at Vacuum State Level 6 mod) and I only own redbook CD's. Before I run out and buy a bunch of SACD's (they are somewhat hard to find, and not cheap) what can you tell me about the sound quality? I understand that the difference between the two is rather large on an unmodded player: what about a player with a high level of mods such as this one? Do CD's and SACD's seem about equal on a machine such as this?

Any good source of affordable SACDs in the US? I see Ebay has a lot listed, and it seems that SACD's are pretty limited to quality recordings, which is fine with me.
dawgcatching
Having heard the SACD on many fine systems/equipment,I'm not a believer.Many will disagree,but I find the high frequencies not-to-my liking.Technology dictates that this should be the way to go-BUT! Multi-channel may be excluded,no experience there.Still a two channel retro-technology person.
On my modded Sony SCD-1 the benefits of SACD are recoding dependent; with some being better than others. In general SACD out performs redbook in areas of inner detail(more organic) within the music and perhaps improved high frequency extension. However some redbook recordings (hybrids) are very good such that the benefits of SACD are reduced or maybe nonexistant.

I believe one needs to know what to listen for to hear the differences and ones system needs to be able to resolve it.

I purchase my SACD's (hybrids) from places like amazon and elusive disc. I listen primarily to classical and jazz (female vocals).

Thanks for the responses. For the multi-channel SACD: does one have to have more speakers than a standard 2-channels setup to listen or to get the benefits? Or, does "multi-channel" have something to do with the mixing and recording?

It sounds like a hit or miss for SACD. I will check out sa-cd.net and see what they have to say. I see alot of the recordings that are available, I already have in redbook. I listen to mostly jazz and classical.
I suggest you check at least one title, for example Stravinsky: The Firebird (Mercury Living Presence SACD)

http://sa-cd.net/showtitle/1687

and then judge for yourself whether your red book CD improvements were worth the money, and how much truth there is behind Boston audio society study published by AES...

:))