Tomorrow afternoon the amps will have been running for the week straight. Already notice some changes for the better. Overall, these are right up there with some of the best amps I've heard for low level late night listening. The noise floor is so low, it's nonexistent. Everything can be clearly heard. Amazing. If anything bothers me, it usually a bite or sibilant vocal. Treble and vocals are getting very smooth. These have wonderful 3D, air, separation, and seemingly limitless power. Very impressive.