Ive wanted the same vids, but could only find this . its the only comparo that is even decent, took me forever to find it. The driver seems to be a little easier on the nismo, hence the lower rpm shift, but you can get the idea if you quickly switch between 2 seconds and 23 seconds:
YouTube - Nissan Z Sights and Sounds
and another of just revving:
http://www.youtube.com/watch?v=XmbRC21MZko
another, just the first few seconds though, not long, but good:
http://www.youtube.com/watch?v=S_U15_hU2yQ
and finally, one one from inside:
http://www.youtube.com/watch?v=OA1CNNEuB14
definitely a night and day difference in tone, not so much volume at all though.