Not sure what the Alpha sounds like, but the Audio Logic does fit your criteria in terms of naturalness, openness and, particularly with the transformer upgrade, slam and bass extension. It is not completely laid-back, I suppose, unless that trait is on the recording, but it certainly is not an upfront, in your face presentation (some of its character, particularly if you don't get a transformer-coupled version, will depend on the tubes you use). It just sounds more "alive" and real to me than most DACS, and does a great balancing act between retrieval of detail and sounding "musical"; from the comments I've heard, the higher level Audio Notes appear to have the same qualities. I'd choose it over the Thor and Jadis, simply because Jerry Ozment designed those units as well and I think he saved some of his best work for his own unit, and at a substantially lower price. Can't comment on the rest of them, although you've certainly identified the DACs that, from the reports I've heard, probably have sound qualities that you're looking for. If you're near enough to my area (northern NJ), you're welcome to come and give a listen to the AL.
