On the other hand most of recordings from my collection sounds similar - and I know it should not being happened that way.
I noticed this too with my IA-7, which admittedly only had maybe 40 hours on it (NuForce recommends at least 70, and my dealer says 190 -- exactly

). In the systems I heard it with (Magnepan MG1.6, Dynaudio Audience 52, and while I was at the dealer's, a pair of Von Schweikert LCR-15s, driven variously by a Jolida JD100 or Electrocompaniet ECD-1 DAC) there was a certain emphasized clarity and a fine crystalline grain in the treble that I was told by my dealer would melt away, which I tend to believe because it was drastically reduced towards the end of those 40 hours. I have to confess at this point that I still find the treble a bit cold and a teensy bit crystalline even on the Reference 9s; it is the NuForce's most obvious un-hifi characteristic, in my limited experience. Regardless, the IA-7 had the classic NuForce informative yet preternaturally fatigue-free treble, which made for a very relaxing listen, and I personally found cymbals extremely natural if not outstandingly extended. I agree with your description that the highs were light and delicate rather than extended or ultra-detailed, but I am surprised you found the mids recessed, because I found the opposite to be the case, particularly compared to a Bel Canto 200.2 amp, which is known to be slightly depressed in the mids.
In any event, the total presentation was beguiling in a way only NuForces seem to be able to accomplish: totally coherent from top to bottom, relaxed, dynamic, and utterly realistic. If the purpose of the IA-7 is to give a taste of the better stuff, I think the IA-7 succeeded admirably.
Me? I'm going to wait until I can afford a pair of monoblocks

.