I have a 500, it has been pretty good. Long battery life. I use a speed sensor on my front wheel as it looses GPS signal under minimal tree cover. I had a 605 with a dead battery. I requested an RMA, a Garmin rep called me and explained that the no longer service the 605. They offered me a trade up for a refurbished 705 for $60.00. I was happy win the service I received.