New 2012 M35h owner checking in. I purchased mine about 2 weeks ago. Put ~500mi on it so far, averaging 27.5mpg with about a 50/50 mix of 70+ MPH freeways and ~30mph stop-and-go backroads (I have a 37mi each way commute).
I did have an issue with the heater not working on the driver's side that Sewell Infiniti determined was caused by a clogged transmission cooler. It was fixed in a day and all is well so far. Now I'm considering the extended warranty. LOL!