oil change price... it's like, WOW!

U235

If you NEED it, it'd be a requirement. This engine isn't brand new, it's been in use in the G37 for a good year now. Usually within a year there's the signs of whether something is going to be wrong.

Regardless, if it turns out there's ANY problem and that the car must have this special oil, Nissan will be responsible for any damage caused by not running it since it's a recommendation and not a requirement. It's not unheard of for entire engines to be recalled (see e46 M3 for example). My point being, read things literally: REQUIRED = NEED TO DO. RECOMMENDED = Optional.

The fact that it's optional means using any other high-quality, proven synthetic is still ok and still exceeds the requirement. If it gives you peace of mind, I say go for it. A regular synthetic oil change will cost you $60+ and it seems others have been able to get Ester changes for $80 so it's not such a big difference. However, at $120 it's bit more of a contemplation.

The valvetrain info is interesting.