I like the clean slate we get from boot-from-scratch. Some pieces of hardware have subtle state corruption issues that can accumulate over uptime (kinda like Windows) that get flushed out by a reinitialization. Instead as much as possible of the boot process should be taken off the critical path and be treated more like hotplug/optional peripherals. Those HDDs? They can spin up while I'm already logged in (assuming they're not the boot drive).