Detlof, you will probably be VERY happy with the Aesthetix, it is one of the few units I have heard which I would put on the same plane as the Jadis equipment and that I would consider as a replacement if I had the money, the space and the inclination. It will probably be a somewhat different presentation, as I think it is a no feedback unit, so it may be a bit more vivid but perhaps with a little less depth of soundstage (we're not talking a big difference in this respect). It does have that musicality and realism that I like in the Jadis. Cwlondon, actually, I have never been as impressed with the Defy 7, at least in its first two marks, as the JA80s. There was more brute power, but it clearly lacked the finesse, delicacy and intangibles that you got from the JA80s as well as the JA30s and JA200s, and the increased power still didn't bring you much better bass control. Plus, you could only run it with 6550s, at least then, and to my ears that is the least desirable tube I've used in the JA80s, as far as sonics go (they do control the bass better, but give up some of the midrange magic). I've heard that the later marks of the Defy might be closer to the sound of the monoblocks, but haven't made that comparison, and my setup requires I use monoblocks; personally, I have not heard a stereo amp which sounds better than its monoblock counterpart (excluding a bridged stereo amp used as a monoblock, which is another story). Also, my comments only relate to the earlier versions of the Jadis amps, not the newer versions which use KT90s, which may sound different. Since I use both the JP80 preamp and the JA80s, and before used the JPL first with the ARC Classic 150s and then with the JA80s, I do believe that there is a good synergy between the Jadis equipment (as I usually find between the equipment of any fine manufacturer) that leads to an overall greater musicality, although it is certainly possible to mix and match to your taste. As far as cables go, Siltech works very well with Jadis; I use a cable called Full Spectrum, which is no longer made, so it's not much help to you, but is very revealing and slightly sweet in the highs, a good match for this equipment. I'm trying out some NBS Monitor Zero tonight which I just bought; I'm pretty sure that will work well, and in the past I've found good Purist Audio and Kimber silver cables to work well with Jadis equipment. The better and more neutral the interconnect and speaker cables, the more you'll be able to appreciate the special qualities these components possess. Hope this helps a little; good luck in your search.
