On my 2.2 system with DLBC I experimented with the correction up to Schroeder (about 200hz, from calculator), then up to the area with more peaks and nulls (about 500hz) and the clarity of the stereo image was better in the second case, but the music had something lifeless about it, probably due to the lower perceived reflections (to which our ear is actually accustomed for that specific room).
These two corrections were with a slightly tilted target, like 0dB at 20hz to -8dB at 20khz.
Then I did an interesting test. I extended the correction up to 20khz, tracing a target that follows the trend of the measured frequency response.
In my case it consists of a dip around 2khz (crossover) and a bump from 3 to 5 khz, then roll-off very rapidly.
This results in little suck of life from the speakers and improved the definition quite markedly. This is probably because Dirac intervened by improving the phase of/between the speakers.
This was a very pleasant and natural sound, as opposed to the straight target line (tilted) which was unlistenable.
Despite this, however, I think the most satisfying thing for me is correcting up to Schroeder. It is a bit blurred but more engaging.
I specify that Dirac allows you to make an instant AB comparison, therefore the perceived differences are certainly valid and not the result of mental conditioning.
So in relation to the subject, it depends on what the correction system does in practice.