Upstart and systemd provide tons and tons of other features though. Restarting of crashed processes, dependencies, etc.. They also generally have much more simple config files instead of start up scripts. I don't know how many crappy startup scripts I've seen over the years, when in practice: set these environment variables, execute this program as this user with these arguments is 95+% of what's needed.
Much much much more straight forward to have some specially formatted comments (?!hahaha, that's the UNIX spirit!) to determine the boot priority and then source some files to read some arbitrary variables and construct the command line that you're interested in running with complete abstraction.
The other functionality may be nice, but 1) it's got no place in init and 2) really complicates a key piece of system infrastructure. Complexity and change are the two dual enemies of stability. As an old-fart ops type, with scars on my hide and notches on my belt, I really hate both change and complexity. The mess with my nines.
Arch and Fedora are relatively wide of my usual ambit, but I've learned in my years to be wary of what others ask for -- you may get it and have to live with the consequences (see: GNOME).
My computer changes location at least twice a week as I commute between my place and my girlfriend's place. A Mac mini serves my needs very well because (including AC adapter) it weighs only 2.7 pounds, and I really appreciate having more ports than most laptops have and not having to pay for and carry around a bad keyboard and a laptop display. (I consider all laptop keyboards bad keyboards, and -- maybe because I am "far-sighted" -- much prefer my girlfriend's 32-inch TV to any laptop display.)
But since the Mac mini does not have a battery, S3 sleep mode does not survive unplugging the device. And since suspend-to-disk is not supported by the OS I run, shutting down is the only option.
P.S., I would have preferred something like a Mac mini, but with a small battery that powers S3 sleep mode. Sadly, I could not find anything like that on the market.
P.P.S., I run OS X on it. If I were to switch to Linux, would suspend-to-disk work reliably?
Well ... you're not running Linux, so systemd is moot (you've got launchd instead, which has certain similarities).
I'm a fan of small form-factor systems, though I suspect we'll start seeing these as G3 tablets (where the iPad was G1, and the current Android-and-others are G2). Which is to say, devices with integrated display and battery, to which other peripherals may be attached (physically or wirelessly, say, by Bluetooth). That said, we're not there yet.
And yes, small form-factor PCs (CPU, no battery, no display) are pretty slick. I'm something of a fan of the FitPC offerings: http://www.fit-pc.com/web/purchase/order-direct-fit-pc3/ (Googling "small form factor" will show you numerous other vendors).
I used a similar configuration under Linux for a time, and as of mid 2000s, found suspend-to-disk worked pretty reliably, though not perfectly. In the past 4-5 years on laptops and desktops, I've had very few problems, mostly traceable to display drivers.
Just because you don't reboot often does not mean it has to be slow. In open source community, people choose their own projects. You can't really expect for force for that matter for them to work on your favorite things.
What is giving rise to the need to reboot them when you do?