Differences in SACD channels

I noticed that when playing two channel SACDs through a
two channel system sounds better than playing a 5.1
channel SACD through a two channel system. HOWEVER, I just started collecting SACDs and my SACD player is not near top of the line(sony DVP-NS915V). Mind you that I only own one 5.1 SACD, I do not want to continue to purchase the 5.1 format if I cannot retrive the same information that the two channel contains.
Any Thoughts ?
Don't draw conclusions from one particular disc.

I do not know any reason why the stereo area of a multichannel SACD should be inferior. (The CD layer of a hybrid is another matter). Given that I have multichannel capability, the only reason for me to listen to the stereo program is curiosity, but they sound OK to me.

A SACD containing only two channels can obviously have more minutes of program than a multichannel disc.
All multichannel Sacd's also have two channel sacd? If you don't want to play the multichannel..then just don't play it. Set your player to default to two channel and thats all it will play every time you insert the disc. You may be a little confused about the format and might want to do some reading on sacd disc types.

Good point by Sogood51. You do need to select the stereo mode if you want to play a multichannel disc that way. If you don't do this you may be listening to only two of the five signals. Although the rear channels might be considered a minor loss (for many discs) the center front usually carries a lot of signal, and it's loss would be serious.

I believe you have, but please let me ask for the question again...........Have you checked if your SACDP has capability to read Multi-Channel disc or not? If so, you need to switch the MC mode to Stereo mode when play back at Stereo system. Otherwise you can only hear 2 our of 5.1 channels sonic performance only.
Thank you all very much your information was very helpful. I just recieved the new Absolute Sound & it has an
article about new digital formats. Asking you guys is easier & more informative.