1.2.0-rc9 enabled CONFIG_FB_VGA16=y in the kernel. This made the console (in Virtualbox at least) much slower. This can be measured as the boot time to the login prompt on rc9 being ~50s, while the same time on rc8 is ~30s.
@LiquidLight also pointed out in the Slack: "another thing that might be related to the console change, getting a screenshot from an ec2 instance no longer works with rc9"