I have been researching getting an SSD for both my iMac and Mac Mini for system drives. After reading a lot of info, I don't think that the performance difference means enough to me to bother with opening the iMac or the Mini and I've decided to go external via USB3. I have decided to go with either the Samsung EVO 850 in an external USB3 enclosure (with UASP) or the Samsung T3 external SSD. Price wise, the EVO plus enclosure would cost about the same as the T3 and I believe that the internals of the drives are similar. Any reason not to just use an external SSD vs an internal in an enclosure? Thanks.