I have a Garmin handheld unit and have no issues with it. Great tool .
However be aware that the maps that come preprogramed on the GBS leave alot to to be desired. Only major streets, state highways, interstates are shown and maybe the Mississippi River and the Great Lakes. So, unless they have changed, you will have to purchase the more detailed program if you want to see streams and rivers. Im using Topo 2008 and it is very detailed and is also good for streets also. Cost $99.00.
And, it is a great tool for mushroom hunting. Go out in a strange woods all day and wonder around when you get ready to leave just follow the GPS back to your truck. Dont forget the fresh batteries at the beginning of a long day. Garmin is powered by two AA's that last 18 hours.