"Do you recall the peak Amperes of the KWA 150SE ? This measurement or Slew Rate are strong indicators on the performance of a Power amp."
There are tons of reviews out there (e.g.
but need to translate it - explains the differences between the 150 and 150 SE)
I'm not aware of any (review) that has detailed measurements. I knew of people who upgraded the 150 to 150SE and there are reported large differences.
The problem with something like that (and remember I still own the LS36.5DM preamp) is of course system synergy. The other problem is that the design is not really new. As with anything, technology tends to improve with age. The 150SE currently lists for $11k. Probably due to its age and other advancing technologies, it doesn't have a particularly good resale value (e.g. just go to hifishark and do a search of sold ones). I'd guess the average sales price is around a third of its current retail. That's fairly low for an audio component that is a current model.
I think that much of the problem is due to the fact that audiophiles have owned it (like me) and tried some of the newer technologies (and my Thiel 3.7s are not an easy load) and realize it is no longer competitive, even at used value. The ultra high end (e.g. well above the current list price of the Modwright) may be a different story. Audiophiles, manufacturers, retail stores, etc., tend to live in the past in many cases. If, for example, they heard an amp of a particular brand and it had a reputation for a particular sound signature in the past (say a decade back, give or take), that tends to stick for a while (I had friends who used to work at retail and that's what they would convey to customers). All I can say in my system, there is no comparison between the modded Voyager I currently own as well as the modded dual mono IceEdge I had before it vs. the Modwright. I've had people over familiar with my system and they concurred.
I think audio wise, down the road, we will be dealing with many more speaker products that are active where one only plugs in the source.