Features aside, when all is said and done the performance of the GPS makes or breaks this device. This GPS works poorly. Mine is slow to acquire the satellites and loses them easily, resulting in inaccurate measurements. After a run this morning, my 301 indicated 8.5 miles while a friend's 305 showed 9.37. One might expect the GPS to drop out under a tree canopy (and this one certainly does) but it also drops out on city sidewalks and even in the shadow of a gymnasium alongside a high school running track.I wish I had not bought the Forerunner 301.