It is a good phone. Build quality is good. Battery backup is also good it will last for 2 days in normal useage
UI is very smooth it donot lag at all but after 3months of usage it started lagging a little bit. Ram is 1.5 gb but it is very optimized
Play highend games on high graphics very smoothly. Low light photography is poor. Screen is very bright Though it has 720p hd display but it can beat 1080p full hd display
Sound output is not good enough. Call quality is good. Looks of the phone is very premium. It has 16gb of internal storage but it is always out of storage space
Some sensors are missing like ambient light sensor. If you want faster ui in samsung than j7 then go for on 7 but it has only 8 gb of storage. Look of on7 is better than j7 and ui is also faster than j7. But if you want games go for j7. If you want more apps go for j7. If you want good screen go for j7
If you want more premium looks go for on7. If you want samsung brand in 11k go for on 7.And if you want more features, more designs, more ram, more internal storage then go for other brands like asus, lenovo, motorola, xiomi etc
Samsung phones are famous for there slim designs, low whight, low sar value, good camerawith good zoom level
If you are concerned with your health then go for samsung or asus because there phones have low sar values