If I have an n1 head unit and replace the brain with an n3 brain, do the solder bypass on the head unit, and add the 70 maps, i would have the same thing as a n3 essentially is that right? meaning i would have the upgraded xm and ipod interfaces and the newer maps, am i missing anything?

That is correct I have the same setup Avic N1 display with the solder bypass and an N3 brain. Works great don't forget to reset eveything after the install

what needs to be reset?

reset the head unit after install to get the new settings from your n3 hide away.

I tried installing an N3 brain on the N1 headunit, and the problems that I had were that the pause button no longer worked while playing CDs, but when listening to the radio, the pause button changed to the "band" and also did not work anymore. I re-installed the N1 brain, and it worked fine then re-installed the N3 brain and still acted up, even AFTER I reset the unit. It'd be nice to know if anyone else was having this problem...