New Windows 10 Insider Preview Fast + Skip Build 18272 (19H1) Oct. 31 Insider

swarfega said:

I thought they merged the streams a couple of versions ago?

I don't think they actually 'merge' streams. I don't think that builds are made for the Rings. Rather, MS maintains several branches of development. These result in various builds. The WU crew can point whatever ring they want at whatever build they want. Fast Ring and Skip Ahead just happen to point at the same build right now. Usually Skippy just goes away for a couple of weeks around a new release, and doesn't accept new members. And there's a window that you can drop out of Insiders altogether once the new release is settled, if you want to stay mainline release.

Fast ring is supposed to be the next release (i.e., 19H1), and Skip Ahead is supposed to be the branch after that, but with 1809 all hung up things are sort of in limbo. When 1809 is properly released, I'm sure Skip Ahead will point to the next branch, whatever code name they give it, destined to become 19H2, and Fast will remain on 19H1..

All done here in a few ~45 mins.
This and the last skippy build hangs under heavy IO when using Intel AHCI SATA disk drivers 11.2.x.x or 11.7.x.x.
Works fine with OOTB Win Standard AHCI SATA disk driver.
I/O throughput seems affected some how, better single thread random 4K @ QD32 but slower at QD1. I think it's due to new Meltdown/Spectre mitigations curiosity of Google?
Also picking up new microcode for this i7-2600, now using version 2E as per Intel August 2018 update.
Seems much snappier than RS5!!!