Please don't take offense, but after being so frustrated with erroneous directions from Garmin and listening to "recalculating", we switched to Tom Tom 920 last year. On sale through Amazon right now for a much better price than we paid at Office Depot.
http://www.amazon.com/TomTom-920-Portable-Vehicle-Navigator/dp/B000VLHN9E/ref=tag_tdp_ptcn_edpp_url
There is a new version now (940). For now, we will stick with the 920 and the new Pro Clip vent mount we recently found that works so much better than a dash mount on a Dodge.
We like the ability to update daily and instantly send in changes we find by connecting the unit to a computer each night. The 920 has voice capability. Unless Garmin has changed, their map updates were expensive and really didn't give us very current information.
What works for one person may not work for another. Also, the 920 allows switching from car to truck to walking to motorcycle.