the new 4runner nav is really nice because it incoporates blue tooth and hands-free. however, recent studies have shown that vehicles with OEM nav systems depreciate faster than vehicles without them. i.e. a new OEM equipped vehicle will cost 2000-2500 more than it's non-OEM equippped counterpart, but 3 years down the road, it will only be worth 500 more than it's non-OEM equipped counter.
I have a tomtom go 910 in my 4runner and i love it. although it isn't the most accurate. street names and everything is fine, but occasionally it's location will be off by a few yards, making the unit think i'm on a different road, because it's maps aren't properly sync'd w/ GPS position. i.e. it will think i'm on the feeder, when i'm actually already on the freeway.