Hi Folks,
The reason for the increased relibility with Google Maps is detailed in the website: http://mobilinc.com/features/geofence/. The reason is due to the GPS being active at the time. Geo-Fencing piggybacks on top of the highest accuracy signal at the time.
Coming home you'll have faster recognition if there are many Wi-Fi nodes in the area visible to your iPhone. Geo-Fencing relies on a lot of external factors (Wi-Fi nodes, and cell towers) for reliability. As a result it will work better for some folks than others. I wouldn't describe that as a bug or a feature, it simply requires many visible RF signals to trigger an iOS Geo-Fence signal to fire to MobiLinc. Because of this it will work better for some folks due to the area and Wi-Fi density they live in.
Wes