I have the 2nd gen and it's been pretty great. I think they should last for at least 5 years.
Currently thinking about getting the 13 mini but I love TouchID too much so it's really a debate between TouchID or better battery life, ugh...
If the thing is built to require a case that would increase its thickness by the amount of the camera protrusion, why not just make it that thick to begin with.
I really pine for a flat back (despite any thickness that would add), square edges, and a back material with a higher index of friction. The SE1 frame was like this.
Good phone otherwise though, fast, battery ok if you charge regularly, etc.