I went to Nissan and they told me that they do a drain and fill.. So they don't compeatly remove all the fluid... This is common.. And they said it was bad to completely take all of it out... After 45k do it again and this is how it becomes less grungy.. So you basically can go anywhere for a drain and fill... I buy the metric S and he will change me 45$...not bad... Need 4 quarts

 

I just got this car and I'm trying to figure out some issue.. Like a ssoftware upgrade and now I'm reading about this ECU reset...my car is lagging when I ecelerate.. Should I do this reset or wait till Nissan tells me to do the update?... Wow this car is touchy

 

Guess it depends which dealer you go to
Even the 14 qts that I used wasn't a complete changing of the old fluid as you drain & fill, let it run and go through the gears, drain & fill again let it run, then drain & fill one final time w/ a final drain off of the fluid, so it's probably 75% new fluid.
I think either choice would be better than not doing anything, but the more thorough flushing with how many miles are already on yours would be a better plan IMO.
As far as resetting the ECU, it's not bad to do and you might notice some improvement, just keep in mind you'll have to reset your seat settings and possibly your radio presets.