My friend used it on Sunday, still hasn't used navigation. He's riding around the neighborhood he lives in, and a nearby MUP, with his wife and kid. He said he appreciates the feature being available if the need arises, but it hasn't been necessary and with the type of riding he does, it probably won't be necessary.
He bought it to have a bike-specific calorie estimate based on HR, and is over the moon about that, everything else is a bonus. He said the elevation feature is a very nice bonus.
So, initial report is very satisfied. For context, he has what many in here would consider a low standard, never having used any competing product. Many in here would consider him a low mileage, not very avid cyclist. I'm saying this so people will have an idea how to interpret his feedback.