Mikey8811, I will try to answer your query as well as I can, although I know I may fall a little short of your need for specific info... I own Vienna Die Muzik; have owned Vienna Mahler v1.5; and have auditioned Kiss several times at length. Any whoolliness or bloat in the bass of Vienna speakers is almost always due to inaccurate placement... And yes, placing Vienna speakers can be a real chore, and is best performed by a Vienna-trained professional. With proper placement, Muzik, Mahler, and Kiss all sound amazing.... Musical, tuneful, and revealing.
Mahler is the most forgiving of the 3, but not the most revealing.... Kiss is wonderfully transparent, but cannot deliver the image density and gravitas required for larger scale vocal or instrumental works, which are instead best served by Die Muzik.
To add to the mix, there should be now a new speaker, called the Vienna Beethoven Imperial Grand... It is housed in a cabined derived from the original Beethoven Grand, but is based on technology trickled down from the Muzik, including a coincident treble/midrange driver, a supertweeter, and (so I believe) 3 bass drivers. It should list for about $10K. I have not heard it yet, but it is my understanding that it it is expected to deliver some of the grandness of Die Muzik at a more conservative price point.... It is worth looking into.
To put things into perspective, the power requirements of these speakers are on the high side, and they like amps that retain their "torque" on lower impedance loads, but they vary a little bit. Interestingly, damping factor has not been a gating factor.... Best results for Muzik have been with an amp with a moderate damping factor.... Here is my own experience just to give you an idea about behavior with amps with different power characteristics... You may extrapolate about possible results with your own amps:
Mahlers.... Used them with magnificent results with Rolwand M7 (350W/8O and very high current), and Rowland M312 (500W/8O and 45A peak, damping factor 1000)... Have not used them with other amps.
Die Muzik: No problem at all with Bel Canto REF1000M monos (500W/8O, damping factor 1000), Rowland M312, and best this faar with Rowland M725 monos (330W/8O, may be 30A peak), and damping factor in 200 range. A little underpowered with Rowland M625 stereo (300W/8O), and markedly underpowered with Bel Canto REF500M monos (250W/8O).
I have heard Kiss in demos giving excellent performances with Rowland M312, Rowland Continuum 500, and a few Boulder amps.... Kiss are also known to match very well with amps that are slightly less powerful like the Rowland M625 (hve not heard this combination).
As I mentioned, I have not heard Beethoven Imperial Grand yet, but I conjecture that their power requirements may be a little more moderate than DIe Muzik and Mahler.