Got mine yesterday too, taking awhile, not the download itself, pretty fast with my near 23 Mbps AT&T Uverse internet connection, but the install. Man first came that Apple logo and the white progress bar. The the screen went black for what seemed forever. I was near to forcing my machine off, but forced myself to be patient, then the next logo & progress bar finally appeared on my MacMini.
Later I out of curiosity, went to Apple's official support discussion grp that I no longer post in, too restrictive, constantly removing posts and warning that they weren't relevant even though they WERE. Also they actually had the gall to force me to change the NIC I use here and EVERY OTHER GRP. I go to and have ever gone to finding it inappropriate, for whatever lamebrain reason>>LOL.
Anyway read over there that quite a few people with MINIs have had a few issues since taking 10.12.4. I think they just let their impatience rule, just not waiting long enough, which was very difficult for me too, having forgotten to get into the PATIENCE LINE, before getting born>>LOL.
One person even used their, "Time Machine, Capsule," to fix their issue, which post I can not find now. Must have been removed for whatever dumb reason, their Moderators use. Anyway, since I don't run an External HD (Don't feel the need since firing MicroCrap Windows from my Life *), I'd have been up a creek without a paddle. Glad I did not have an issue. May have, if I had done a forced power off, in the middle of it
I'd share the URL of that post over there, but not sure if that is allowed here. Don't need another hand slap>>LOL.
* I have two machines in my Life now, after firing MicroCrap (Had a Windows XP machine that I had converted to Linux Mint 17, before retiring it New Years day, buying my Mini), and the Chromebook I am typing on, this moment. Neither one do I run an external HD, since I am not a collector of STUFF on a PC, and the little I do not want to lose is up in a CLOUD (Google Drive for this CB) , and ICloud for my Mini. Also I have the same or more stuff on a stored away FLASH DRIVE.
Also still have my OLD Windows XP converted to Linux retired desktop, stored away. I have not taken a sledge hammer to its' HD, YET
Soon also will take delivery of an
Amazon Fire HD 8 tablet, just for convenience sake, which has three times the RAM that my last joke POS 7" tablet had, that I finally lost it on, taking a hammer to THAT, near making the battery explode>>LOL.. My way of making sure that no one can come across it and use any personal data