I own one of the cd players you reference, (the Opus 21), and directly compared, in my system, another one, the Audio Aero Capitole II.
I feel that the Capitole II is just slightly better than the Opus 21, especially in the mid-range, as it sounds slightly more like analog to my ears. (The Opus 21 already sounds somewhat analog-ish (assuming that is a word!), which is one of the things that impresses me about it. In case you are wondering, I listen mostly to LPs, and so I much prefer the analog sound to digital.)
However, I would like point out a couple of differences between the two.
One, the Opus two has a regular front opening drawer, whereas the Capitole II has a top loading drawer with a sliding cover, and when inserting the disk, a "puck" must be put on top of the cd. I disliked that aspect of operating the Capitole II, to the point that despite it was slightly sonically better than the Opus 21, I felt it was not worth the hassle to upgrade to it. And two, the cost of the Capitole II you list is the used price, whereas the cost of the Opus 21 is the new price. (Used they typically run just a bit over $2K.) Which means that, IMHO anyway, that the Opus 21 is a better bang for the buck cd player.
Another player you might want to put on you list is the EMM Labs CDSA. It is a wonderful redbook cd player, and it is an incredible SACD player to boot! There was one listed here on Audiogon for a good price of $5,550, but unfortunately it sold.
Good Luck in your search.
I feel that the Capitole II is just slightly better than the Opus 21, especially in the mid-range, as it sounds slightly more like analog to my ears. (The Opus 21 already sounds somewhat analog-ish (assuming that is a word!), which is one of the things that impresses me about it. In case you are wondering, I listen mostly to LPs, and so I much prefer the analog sound to digital.)
However, I would like point out a couple of differences between the two.
One, the Opus two has a regular front opening drawer, whereas the Capitole II has a top loading drawer with a sliding cover, and when inserting the disk, a "puck" must be put on top of the cd. I disliked that aspect of operating the Capitole II, to the point that despite it was slightly sonically better than the Opus 21, I felt it was not worth the hassle to upgrade to it. And two, the cost of the Capitole II you list is the used price, whereas the cost of the Opus 21 is the new price. (Used they typically run just a bit over $2K.) Which means that, IMHO anyway, that the Opus 21 is a better bang for the buck cd player.
Another player you might want to put on you list is the EMM Labs CDSA. It is a wonderful redbook cd player, and it is an incredible SACD player to boot! There was one listed here on Audiogon for a good price of $5,550, but unfortunately it sold.
Good Luck in your search.