I got the 650 a few months ago, and generally it has performed very well. I live in San Francisco, and two days ago, for the first time, I drove with it downtown. Now surrounded by very tall buildings the Garmin got completely confused. It generally had no idea of it's location, and the driving instructions made no sense. It had to continuously recalculate the required route, and the recalculations were meaningless. Once out of this area, operation resumed to normal. Now I understand that perhaps because of the tall buildings, satellite acquisition may have been poor, but still I expected better performance. Was just wondering if anyone else has experienced similar issues with their GPS, regardless of brand.

Thank you,

Update 3-7-08: Purchased a Gilsson external antenna for the Nuvi, and the problem was solved. No reception problems downtown, and much faster acquisition of satellite signals on power-up.