Unless you're on an unlimited data plan or are just a maniac about getting every new Apple Product each year; get the Series 1. Looks just as expensive and new as all other models and works just as great. No slow downs or seemingly large differences between the two. If you are looking for phone connectivity while you're away from your phone, you'll need a newer model. This works via Bluetooth so you'll need your phone in a decent vincinity of the watch to keep everything moving. Which technically is fine, as most of us usually always have our phones on us or around us these days.