Hi Er Stifler,
Personally, i'd choose the Huawei Honor 5x. If you're a gamer and loves to save music and photos this will be the best among the two.
Though both phones almost have same specifications, Xiaomi Redmi Note 3 has a better design, higher battery but the only downside is, there's no SD Card slot. If you're into saving pictures and downloading applications it's much better to choose the Huawei Honor 5x. You just need a micro sd to expand the memory of your phone while compared to Xiaomi Redmi, it has limited space.
Hope this helps!