First; I run the same software on all my computers for around 15+ years; some libraries etc have been added ofcourse but basically I develop with vim in python, c#, java, c&#x2F;c++, haskell, haxe, ruby, perl, php etc and the Chrome browser since it was out. The software on the Air would be completely identical to the software on the Pro. So not sure how it can be &#x27;my&#x27; software; it&#x27;s software for sure, but what  I don&#x27;t know.<p>I am making statements of what I observed. If benchmarks show that the Pro is faster but <i>to me</i> it feels slower would that matter to me? Not really. I do not do 3d work or video editing and maybe it is faster in that; to <i>me</i> while coding it just does not feel as snappy and I can just show the beach ball to you on the pro while I have never even seen it on the air during work.<p>But that is nothing compared to the battery life; this is not subjective; I just get a few hours out of my macbook pro&#x27;s battery while, again with the same config, my air did basically all day (6-8 hrs) and my x220 does 12-13 hours. OpenPandora does an easy 10 hours. The 2015 pro is <i>by far</i> the worst I have while for me battery life is more important than speed. I really don&#x27;t need speed for what I do even while devving games (2d).<p>Whatever the issue; I will never buy that again; Apple did do nothing to help even though I showed them, in person, the issues. I might buy an air again though ; especially if the battery life improves to 12+ hrs.