When I started also like you, want best bang for the buck. But I can only share what I used:
#1 Mi Band2 - Cant measure heart rate real time. Dont buy
#2 Mi Amazfit Bip - Can measure HR real time(my only real requirement). Lodged 1000km+ now still going strong. Battery still ok (6-7d). Can see map/route. Many stats per run to see. Can store all run records in Mi App but not Stratos ya.

I bought two years ago, rm245. Check out credit cards offer, a friend of mine get this free just by sign up.