I have a 2010 17" mbp i7 but only 4 gigs of ram. This was my test machine. Upgraded El Cap beta first and all was well except for Chrome. I then did an erase & fresh install of Sierra with the same results. Other than Chrome, nothing worth mentioning. So I decided - what the heck. Upgraded my late 2012 mini, i5, 10 gigs of ram single drive and also no issues except Chrome. It's been very stable and caused me to rediscover Firefox, although Safari runs very very efficiently. Holding off on my main mbp retina, however, since it's also my work machine. Give it a week & I'll probably say what the heck again.