As you can see from 2 photo above, see how the heatsink in ZTE MF680 is 2 divide piece and E372 is one whole big long piece of heatsink ?
This is the main reason why you guys feel ZTE MF680 is hotter than E372 because the heatsink too small compare to E372 can't hardly tame the whole heat , and the zte mf680 cover will get much more warm and need a cooling method or else performances is drop. on the other hand E372 doesn't need any cooling method and will still be fine and performances a lot better and much stable when heat raise,..