i use the garmin foretrex 201, and find accuracy is normaly down to about 10 ft. the altitude function shouldnt be an issue for those using gps for kite sports, i now i am at sea level when im stood on the beach. if you want to know your speed and distance travelled also direction + max speed then this unit is for you. BEWARE BUYING FROM EBAY as US units are designed to pick up satalites theirfore you could have prolems with accuracy im told, this could be the problem with the reviewed units.