However, as you've noticed, each device feature set is determined by overzealous marketing. My Forerunner 245, despite having tons more memory than my ancient Fenix 3 and considerably faster, has less data screens for running. It doesn't have an altimeter, but the cheaper Vivoactive series has an altimeter because fitness users want to count floors climbed. It has Bluetooth but is not allowed to connect to bike power meters, because then it would overlap with Garmin's much more expensive triathlete watches.
This leads to app store problems, because each app and watch face has to be explicitly compiled for each watch - even when the watches have the same display size and feature set. Buying a new device often means that you'll have fewer options than someone with an older one.
