We did notice a substantial lag in the shutter performance. Three quick taps on the camera produced just one image, which showed just how slow the camera is.
Then again, the pictures themselves are okay in direct sunlight. But the ones we took in low light conditions were not good at all.
And here are some Geekbench benchmarks of the Redmi 3S Prime, which is the 3GB RAM variant.
The Redmi 3S clocked in a score of 614 points in the single-core tests, and 2660 in the multi-core tests in the Geekbench 3 benchmark.
The Redmi 3S does perform well without many hiccups, but it is not as fast as the Redmi Note 3. But that's what you get for the price.