I just bought my wife a 4 series but I haven't played with it yet. I got her the cellular model which will up her cell service $10 monthly. I do love the idea of being able to hop in the boat or run to the grocery store and the watch will get you by. The only part I really can't wrap my head around is the battery life. The idea that I want to use the watch to track my activity during the day and my sleep at night. When do I charge it??? That's the only reason I've held off. A lot of people love them though!