I'm looking for a portable navigation under $200. I've used some crummy units in the past. One of them would tell me to turn the wrong way into a street, and its directions were very confusing. With another one, if you missed your exit it would recalculate a new route but it was so slow that you missed the next exit before it figured out the new route, then it would recalculate again, and again, and again. What's a good unit?