I have had my mac for 1.5 years now and been stuck on the fence between which one to buy. Both are on sale right now and I saw from another thread that both seem to work with the pre-release beta of Sierra that went out to the devs. I can't afford to keep buying different software, so I'd rather get it right the first time and have a software that works. I have had VERY bad luck with Yosemite and El Capitan, so I hope that if I upgrade to Sierra, I can have an OS that works reliably on my 2014 iMac 5k and not need to upgrade again. Any help of why one is better that the other from people who use it would be appreciated.