the extra wheel is a definite safety factor. switched from diamond to a greenspeed gto two years ago and it's great. still need to watch the traffic, but there is no way you are going to fall off a trike. you give up some speed, but then it's great to up a hill as slowly as you want...stop for a minute to rest if you want to--and then continue up the hill. no need to unclip when you come to a stop.