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 ?