Not necessarily Ron, a system is limited by its weakest link, and it cannot make any component sound better than what it is capable of. I'm sure the Sony changer is a nice unit and works well in a mid-fi system, but it would probably limit the potential of Tysons's system.
True, the weakest link is the key. But in order to obtain better SACD perormance than the 555, you'd have to spend almost 3 grand for the 777. For its surprisingly affordable price (I think it used to retail for 1200), the 555 is quite admirable. Just do a search on HTF on it, and you'll see many accolades. From ppl with better equipment than mine, too