Outside it needs a few minutes to get a fix on a location.
In a moving vehicle it just won't work.
The Navman - just works. You start the car first and then you turn on the GPS.
When I just got the phone, it worked v quick, I was surprised, I was in a moving vehicle. But I found out the default settings had A-GPS on.
FWIW, I also have a Garmin 60CSx which has the Sirf chip, maybe b/c it is more for outdoor hiking and stuff ... in a car I found it also worked slower than my Navman.