There are some rumors of software only features on the new "Pro", the biggest of which is some kind of hiking feature... I suspect it will be built in terrain maps similar to what Garmin offers on their Fenix 7 / Epix 2 watches (their highest end, they incorporate ALL the features of running, biking, swimming and other lower end watches and cost $1000 featuring titanium, sapphire, and lengthy battery life). I think the idea behind the watch from Apple is bigger screen (47mm is standard in the "sports watch" world), rugged (but not necessarily rugged looking, this is Apple after all), more sport/hiking specific features (hiking terrain maps, rumored yet to be announced offered coaching plans etc.), much improved battery life offering up to 24 hour GPS recording and 3-4 day battery regular battery life (if you aren't using GPS much.) Most folks will think the extras aren't worth it or useful to them, and the price will be a put off... but the folks who own iPhones but have been buying $1000 Garmins (MANY MANY FOLKS) will suddenly have an alternative in the Apple ecosystem.