Ok, so thanks to Teide that has made the Nebula impulse and thanks to Dimitar that reamped my stupid preamp tracks using it, I've been able to make a short comparison between this two technologies...
I've basically extracted the "static" impulse using the tracks processed by Nebula to compare them at the best...
Sadly the impulse is not a great sounding one imho (sorry Teide), but it's pretty good for a test like this...
Here is a snapshot of a frequency analyzer just to show how similar are the Nebula impulse and the one that I've extracted:
http://www.filefreak.com/pfiles/42577/NebulaVsImpulse.jpg
Here are the comparison samples:
http://www.filefreak.com/pfiles/42577/Nebula.mp3
http://www.filefreak.com/pfiles/42577/Impulse.mp3
What do you think?