What's the best Sony CD/SACD player?

Based on that description, I'd choose the Linn hands down.

I tried to be as objective as possible, but my bias was probably showing in my short description. I like the presentation of Linn as well. But I probably have under stated XA5400ES somewhat. The detail retrieval and increased midrange texture on Sony cannot be ignored. What's even more amazing is that the higher detail is heard without sounding bright or edgy. If anything Sony is darker sounding than Linn. For me I actually prefer Sony's presentation because 1. I'm used to Linn and was looking to get something different to begin with. and 2. I was looking to improve red book CD playback with more detail, and get more textured midrange overall, and Sony hit the sweet spot.

True, the choice of adjectives I used probably was confusing. When I say darker, sometimes I mean tonal balance, and I also use darker to indicate the blacker black background / lower noise floor. For example, when I played Friends of Carlotta on Unidisk I thought the sound was detailed, but sometimes it was "shouty" or somewhat congested. On Sony I thought it was less congested, also there was more of the small ambiance of the recording studio. Could be due to lower noise floor. Could be from better detail extraction. Another reason I used the word darker was to emphasize that Sony is not a bright sounding player. But anyways I should just stick to more objective side of the impression than using colorful adjectives that could be confusing.

So is there any reason to look at older Sony units like the SCD-1 or XA9000ES vs. the new 5400ES? Seems like used XA9000ES players are around $1000.

Only if you need 5.1 analog outputs.

Kal