For the last month or so when my Refurbished MM(Late 2014) 2.8GHz, 8GB Ram, 256SSD opens-up Safari that "Beach Ball" is is spinning-away more often than not. It lasts for a few seconds and then goes-away. I bought this unit from the Apple-Online Store in June, 2015 and has been a stellar performer. However, is this the first sign that my SSD is starting to fail?? My AppleCare on this MM expires in June, 2018, so, I may take it in for a check-up if this continues with a Apple Distributor as we have no Apple Store here in Costa Rica.