Hi Rooze,
You are quite right. The stock Carver is an OK amp for the money, but reaaly fails in complex musical passages with massed instruments, is very lacking in detail in the mids and highs. There is little to no depth or width to the soundstage, no separation of instruments. Microdunamics aren' tthere, macrodynamics are just OK. The bass is its stongest point.
However, the EA modded Carver is a whole new ballgame. I heard earlmarc's EZ modded Carver driving Maggie 1.6's and was mightily impressed. I also brought my stock Carver along for a direct comparo. Earlmarc's amp was very open and extended in the mid's and highs, had incredible soundstaging and instrument placement, good micro and macrodynamics. Couldn't tell much about the bass with the 1.6's.
I then sent my amp in to Steve for modification. After 250-300 hrs on the amp, I couldn't be happier. The bass is really tight and extended. I can't honestly say it beat my old amp (a Spectral DMA-200 in an all Spectral/MIT setup), but it cost a LOT less money. The Spectral beat it in micro and macrodynamics, and just about everything top to bottom, but the Carver is sweeter and less fatiguing. I believe the Carver may also have more depth of soundstage.
Bear in mind, I have never listened to any of the other super amps you are considering. I will say that earlmarc's comments are pretty darn spot on, with as little personal bias as is possible. Earlmarc states what is there regardless of who owns what equipment (including his own) and is not a person given to hyperbole.
Bill