well its a mix
oneplus 3 has highend specs 64gb and 6gb ram but no sd card,5.5 inch amoled display a good cam but battery sucks as it has less battery than oneplus 3t, 2ndly android o will be the end for oneplus 3/3t as per oneplus forum and as it z without warranty so no parts available here
honor 8 has lot better battery than oneplus 3 , though in benchmarks it is less than oneplus 3 sd 820 but in real life you wont feel a difference, 4gb 32 gb in local warranty with parts available, honor 8 cam z far better than oneplus cam,and it also has sd card, but IPS display though quite good but oneplus has amoled
rest you decide