The choice of macbook for swift development under IOS?

Question

macbook

I choose macbook for development on swift. The budget is small, it becomes a choice between the MacBook Pro 15'' Retina (2015) [MJLQ2] and similar MacBook Pro 13" (2017) [MPXR2]. The question is in the performance and quality of the keyboard.
I would like to hear an opinion whether any of them for development in XCode.Won't it take 5-10 minutes to build and launch the simulator (naturally, at the initial stages, not high-loaded projects)?
And the second question, if firmware 2017 will be enough (I don’t ask about the diagonal), is it worth the risk because of the "butterfly" even the second or third version? Was it really fixed or did the problem remain? It scares me that at flea markets the most "popular" ones on sale are firmware 13 2016-2018. Thank you

Answer 1

MacBook Pro 15'' Retina - just her.
in the 17th year, the butterfly had not yet been fixed, the problem was in the color and alloy of the metal membrane, which was rusting. I have repeatedly published photos of membrane corrosion here, the alloy of the membranes was changed only in the 18th year.
And of course, the 2-core i5, although newer in the 2017 models, will still be several times weaker than the i7, even the stock 15s of the 15th year .;

Answer 2

If at the initial stages they are not highly loaded, take a fresher macbook .