I've been extremely satisfied with my N360 (except the shifter*). I have about 5000 miles on it, including a 3200 mile self-supported tour. The rest of the miles have been commuting and utility use.

If I was having the problems the OP has, I would first verify that the shifter interface was installed properly, allowing the lowest gear ratio to be accessible. Since the hub is relatively rare, most mechanics aren't familiar with them, and a mistake could easily be made in this subtle aspect of the installation. Due to the nature of the CVT, the mistake would be hard to detect while riding. The hub would seem to be working properly.

* At around 1500 miles, I replaced the NuVinci shifter with a Rohloff shifter, and have been very pleased with it.