I tested by leaving the receiver in one place for one hour after resetting the track log and trip computer. I tested with WAAS off and battery saver mode off. These are the results:
Indoor stability test
Reported accuracy: ± 28 feet
Reported moving time: 9 minutes
Reported distance: 12.5 meters (41 feet)
Outdoor stability test in an open area in cloudy weather
Reported accuracy: ± 15 feet
Reported moving time: 0 minutes
Reported distance: 0 meters (0 feet)
Outdoor stability test in an open area in cloudy weather – inside backpack
Reported accuracy: ± 15 feet
Reported moving time: 2 seconds
Reported distance: 1.22 meters (4 feet)
Comparative reported accuracy test
Nüvi 350 compared with 60CSx – 33 feet vs. 15 feet accuracy
6 satellites for Nüvi 350 compared with 8 for 60CSx
Measured in open field under cloudy sky
(Also note the Nüvi screen is less clear due to being a touch screen)
I tested by setting the receiver to log the track position every 10 seconds. I packed my backpack (a Golite Jam2) with a representative load and placed the receiver inside the backpack with the antenna pointed up. I went for a ten-minute hike in a semi-wooded area on a cloudy day. The receiver was not impeded by being enclosed in the pack, but was able to record its position every 10 seconds. I repeated the exact same hike with the receiver attached to the shoulder strap of the pack, with the antenna pointed up, and overlaid the two tracks on the map. They matched perfectly. Due to this result and the results of the positional accuracy tests above, I concluded that reception and accuracy are not degraded significantly by keeping the receiver inside my pack. This performance was very impressive to me.