Let us start with sim card. It support dual sim which is very good for every dual sim user. Many people use two different phone one for calling and another for media and other things.
Don’t worry this phone solve your problem . as my opinion its display is very good very bright and color full just love this machine display under this price range.
Most important part camera which is 16 MP, f/2.0 very good for day and low light picture. it also have some other feature like 1/2.8" sensor size, 1.12 µm pixel size, geo-tagging, touch focus, face detection, panorama, HDR. front camera is also good for every perfect selfie(8 MP, f/2.0, 1/3.2" sensor size, 1.4 µm pixel size, 1080p)
last part is all about the battery(Non-removable Li-Ion 3000 mAh battery) I am used this phone continuously 5 hr not much heating issue . 820 play very good role . So I will rate this product 8/10.