So I decided to go ahead and get my transmission serviced but every Nissan or Infiniti dealer in my area have all but refused to change the fluid. They say they do not recommend changing the fluid on this model because is actually decreases trans life.
​​l have over 50k now and want the fluid changed but definitely don't want to cause any issues with the transmission but I just don't trust not changing it either. Are there any differences with my trans vs g37? Any suggestions?

 

Your AT is the same as the G37 AT, might be newer software updates applied but that would be it. This topic is discussed pretty often, the AT is serviceable, there is a specific procedure detailed in the FSM and under severe duty schedules it IS a recommended service, at least in my 09 manual. It's about a 50/50 chance you'll have a dealer tell you it's a sealed unit that requires no service and others that routinely service their customers ATs. I DIY'd my ATF at 70k miles and did notice better performance, especially in hot conditions. Might check a NIssan dealer if the Infiniti dealers aren't wanting to do it.

I would recommend it, but only the service in the FSM which is a 3x drain & fill. Some places have pressure flushes that isn't something that's in the FSM and may cause issues.
Also when doing the service see what they charge to drop & clean the pan, I would do this if you get to 70k or more miles.