On the road traveling, I’ll have more to say when I return home.
I did not get everything I wanted, but the newly announced iMac 5K Pro looks great, with a monster graphics card, support for up to 128GB of ECC memory and 4 Thunderbolt 3 ports (unclear if one bus or two). Available in December 2017.
Apple also announced new MacBook and MacBook Pro models and various other software stuff.
More significant to serious users is that APFS will become the default file system in macOS High Sierra. MPG strongly advises NOT upgrading to this file system until it proves itself for at least six months, particularly hard drive users.