I disagree about nginx being more difficult to configure than Apache. Apache's config file was terrifyingly complex to me when I first started using it.
Especially when you add in the fact that most distributions add in their own flair to configuration (like the location of config files). Unfortunately this is beginning to happen to Nginx as well, but for the most part the guides out there are agnostic and offer help for anyone looking to config nginx.
A lot of that is the fault of the distributors and/or the default "put everything in and comment it out" style that apache ships it in. If you actually sit down and figure out what options are required to serve content, it's not so bad at all.
It's nice to see linode's library finally catch up to slicehost's articles. For a while it was really bare but now I prefer it over slicehost as slicehost articles is starting to become cluttered with all the old distro specific categories. One thing that is still missing from linode's library is nginx.
One thing that I have noticed about slicehosts articles is that they really just cater to two markets, the rails market and the php market and what they do is lump rails/nginx together and php/apache together.
While this is generally okay they really don't need 7 different articles on how to configure Ubuntu 8.04 9.04 9.10 and Debian to do the same thing, linode at least dumps ubuntu and debian together.
What I wanted to see was a current comprehensive guide on going beyond the single server setup and things like nginx + PHP using PHP-FPM.
I also wanted to see guides for HAProxy, stunnel, NFS and anything to help make iptables easier.
It's not that I can't forge on and and figure it all out, it's that I want to be able to quickly repeat what I do and to spend less time on server admin and more time on application development.
I also found this incredibly useful... make HAProxy your virtual hosting manager (I serve 10 sites off of 4 web servers and each site is just identified by a different port number on the backend web servers):
http://www.techrawr.com/tag/virtual-hosts/
I agree we need easier-to-use documentation on this stuff, but have you considered documenting what you've done yourself? I started keeping a notebook of helpful tricks back in the 90s. By the mid-90s I was publishing some of the info, and by the late 90s I had friends working with me to create articles. This was when the e-Zine was still pseudo-popular as a channel of self-publishing. We later went on to blog format, but the results are the same:
Your brain forgets little, but loses references to information it hasn't needed to use in a while. Documenting things (which includes proofreading and maybe even testing your documentation), uses repetition to solidify those references. Some people learn by repetition better than others, but even if it's just penciling apache config tips or iptables examples into a Moleskine journal, writing is often one of the best ways to memorize things.
The things I've written down are the things I remember best or at least they're the things I find easiest to come back to. It goes for the awk recipes I've jotted down, database tuning parameters, and even automotive repair tips.
From a quick look, I can say that at least half the things listed on the article can be done on Windows Server through an intuitive GUI interface.
The simple fact that newbs and admins alike will never have to lookup the man pages for arcane commands to accomplish simple tasks like setting the timezone (dpkg-reconfigure tzdata) is a big difference in terms of usability.
As a Windows and Linux administrator, I'll say there's nothing intuitive about a GUI or the random ways they change from version to version; I'll take a Linux box and text files any day, it is vastly superior and easier to manage than a bunch of windows boxes. Frankly, the best way to manage a Windows machine is to install Cygwin, ssh, and cron and pretend it's a Linux box.
I used to work in a Wondows shop and configuring things like IIS was always a giant pain. I could never remember which of the 14 tabs the setting I needed was on.
the other side of the coin is I can administer a server over a text based connection with linux, and I need a bandwidth heavy and low latency connection to do remote GUI admin for windows. Not that anyone would any more but you can fairly easily administer a unix server over a 56K modem still. Windows, not so much.
And once you get it, the console has a lot of expressive power that isn't as easy to reproduce graphically.
Command line: here is an alphabet, grammar and dictionary. With these, you can utter any command, submit any query, and make automatic decisions based on the results of any command or query. You can also create your own grammar and dictionary; recurse as desired.
GUI: here are the sentences you're allowed to utter. Which one would you like?
Actually, having a bandwidth efficient channel for managing your machines still matters. I've fixed servers using an ssh client on my phone, and while it's obnoxious and not my preferred mode, it's not as bad as having to find a place with a decent internet connection when you're on the road.
Ten years ago, I was a Windows Server admin and Win32 developer. Honestly, in the years I've spent with Linux since then, I can't imagine going back to that world.
While I think your argument is very valid for consumer-level interfaces, I don't think it holds for more skilled and specialized tasks like server administration.
Someone who's never done it before should be following a guide regardless (for security reasons if nothing else), and if you set up servers often enough that you don't need to at least glance at a guide or checklist to make sure you're not forgetting something, even the more arcane commands are going to be second nature to you.
The locations and names of things in those GUI interfaces tend to change (a lot) in the Windows World, whereas there tends to be less fundamental change (although some for some distros) in the Linux/BSD world between releases.
I'm not suggesting that a GUI is better than command line or vice versa (different strokes for different folks and all that) but that having less change for critical files has saved me a lot by way of time.