For iOS development which system would be preferable. The options are 13" Mid-2017 i5-7360U with 8GB RAM or 15" Mid-2014 i7-4870HQ with 16GB RAM. Personally I'm leaning towards the 15", but I'm not sure that's the best choice. I can say that the 15" is in perfect condition and has only ever sat on a desk plugged up the entire time my company has had it. When I checked it's battery cycles I was very surprised to find that it only had 2 cycles.