Haven't been in my car again until this morning, and I finally got a chance to test out Sprint Nav... I'm going to say that it works better than it ever did on my Pre-. The GPS seems to acquire quicker. Actually, I avoided using Nav on my old Pre- because it was so unreliable in getting a GPS lock. Maybe I just had a bad Pre, I don't know. But I read someone else in this forum observing a difference in Pre 2 GPS performance. Man, this phone just ain't lettin me down!
I think Sprint Nav on 2.1 is a better build than the 1.4.5 version, I loaded it on my 2.1 Pre- and noticed Nav works a heckuva lot better than it used to. All the advantages you described I've noticed on my Pre-.