I'm very happy with a middle way, the 200 EUR Withings Steel HR Sport, considered a "hybrid". Good usability and excellent 20 ... 25 day battery lifetime. Will run even longer if you synchronize it sparingly.
It looks like a regular mechanical watch at 40mm, with two complications: a step counter, and an AMOLED screen for notifications and other readouts. Supports the usual functionalities: pulse meter, step meter & other sports tracking, visual & tactile notifications and Bluetooth synchronization with smartphone.
About the only think I would add to it is time synchronization from atomic sourced radio signals, to make it truly independent from a cellphone for extended periods of time. Mine tends to drift about a minute ahead after about a month without phone synchronization.