The reviews (4) at Amazon are currently mixed. Here is a partial quote from the one star review.
Then, when you are traveling and you miss a turn, it will again load maps. While the Garmin takes several seconds to recalculate your route, the WorldNav can take 5 minutes or more, especially if you make the mistake of creating a new route and change your settings from "Motorcycle Prefer Freeways" to "Motorcycle Avoid Freeways'. Every time you ignore a direction to turn on a dirt road it will again load maps. It will spend more time loading maps than providing directions.
There is more than one listing for the same device, the other ones I found had no reviews.