Actually the cameras are the main reason I went with the 7+ over the 7.
I use the longer lens cam more then the faster wide lens cam. As I mentioned the camera app (and all of the 3rd party manual apps that I've tried) allows me to choose which cam (or use both at the same time) regardless of the lighting conditions.
For me and for my uses of the camera, the camera on this iPhone is the best of any cell phone camera that I've ever used with the possible exception of the Lumia 1020 years ago. I've used many Android, Windows and BB phones over the years. I had a Samsung S8 when I bought the iPhone a couple of months ago. I sold the S8.
My lady friend, who has been a Samsung girl for years, starting with th S3, said rh same thing after she saw and tried my iPhone 7+. She now has one also and has sold her recent S8.
Thought S8 has similar feature and with more control.