hi dan. i tried it (the extreme version) across my entire system (pc, ic, tube pins etc). At first things were bright and forward, but with continued use, that feature resolved and i was left with increased clarity, articulation, and speed - yet i dont think any harshness or glare was introduced. Like every other maneuver that increases these aspects, the system should be "up for" increased exposure and transparency. Overall i think well balanced systems would benefit more than those with underlying tendency towards stridency - "more is not always more." As i recall, your system with the FS (and rowland was it?) would not have this issue....
Having said all that, overall i did hear a real benefit. whether it was $149's worth or not is a case by case individual decison, but I would say yes for me. They offer a money back guarantee, so it might be worth a spin.