I got my J7 at a Black Friday sale in 2016. With T-Mobile moving towards 4G LTE, my 4 year old S3 only did 4G, not LTE. But my S3 was too old to get the "no monthly charge" trade in for an S7, so I have to pay about $7/mo for 2 years for the J7 when it was on sale. They would have only given me $7 trade-in for my S3, so I kept it for backup (no mobile service, but still works on WiFi for Internet things).
I did not realize how slow my 2-core 1.5 GHz S3 was until I got the 8-core 1.5 GHz J7. And download speed where I am is about 40 Mbps and 18 ms ping with 4G LTE vs. about 15 Mbps and sometimes 350 ms ping with just 4G. The J7 is somewhat larger than the S3, so it is easier to type in passwords and easier to see things, but T-Mobile had a tight protective case that does not add much bulk. It doesn't have auto screen brightness, but a swipe and tap can adjust brightness and you can make the screen very bright for outdoors, I usually keep it set near minimum.
Not sure what somebody's problem was with the GPS, but if you actually have the GPS turned on it should work better than triangulation from cell towers unless you are some place that blocks high frequency GPS signals. I rented a Pontiac in California long ago that either had some sort of metallic window tint or windshield heater that blocked GPS. At the time I had a Garmin 45 (from 1995) that had a BNC mounted swivel antenna, so I was able to pick up a BNC window mount cable at Radio Shack and mount the GPS antenna outside of the car. But with the cars I have, I can set the J7 in my console cup holder and the GPS works fine for Google Map directions. The J7 does not have built in compass, so it cannot tell what direction you are facing unless moving.
The J7 may not have all of the features of the S7, but at significantly lower price level, I like the J7.
