Just did a relatively painless update from 10.13.2 to 10.13.3 on a GA-Z170X-UD5 | i7 6700K | GTX 950 (iMac 14,2). It seemed as though most issues in the forum were around the GTX video card, so I unplugged it, updated, then plugged it back in and installed the current nVidia drivers. I haven't...