I have long been a user of tiling window managers. They provide a distractions-free environment, and as my work-load has been increasing, so has the number of distractions that the Linux desktop can throw at me. Sometimes it's a good thing to shut everything out and get to computing.
The number of frills that i3 comes with is SO low in fact, that it doesn't even offer a clock! When you log in you will see a minimalist interface kind of like this (minus the bar at the very bottom, that was my idea and I will cover that later)
It is very important to realize that i3 has a VERY steep learning curve that will gobble you up if you don't put in some effort. The end-all-be-all guide to i3 is http://i3wm.org/docs/userguide.html, the i3 user guide. It will instruct you on everything you could possibly want to do with i3. It explains the philosophy behind the window manager as well as how to use it, so poke in and read around even if you aren't an i3 user (yet).
The advantages of i3
i3 is peculiar. When you first start opening windows, you will notice that it doesn't do what you would expect from Awesome or dwm. It actually uses all of the screen evenly.
This provides unparalleled customizability concerning the way that you, the user, arranges the windows. Think of i3 like you would think of GNU screen or tmux, just for X clients. The reason is that each of these "containers" can be further split and assigned splitting rules, so that a user can emulate the one-big-many-smaller paradigm from awesome or dwm.
|A mess I made playing with i3|
The disadvantages of i3
Disadvantages in i3 are PEBCAK. Everything can be solved in i3 with the well documented protocols and extensive configuration file. However, there are some really hard problems to solve that are not there out of the box. For instance, i3 does not come with a clock (although it does come with a system tray, thankfully!). To combat this I wrote a program that can be evoked that reads the time off (espeak piped into a C++ program using strftime) and put tint2 on an infinite loop (i3 will kill tint2). Are these solutions? No. There should be a textclock widget like in Awesome. But this, like the rest of i3's problems, can be solved with a bit of ingenuity and elbow-grease.
As a control-freak, i3 is seemingly a nice tool to take full control of your window manager. There aren't any distractions, the key bindings are sane, the RAM usage is super low (< 5 MiB), and it is oh-so-configurable. It is a lot of effort, but if you are fed up with the glitz and glamour of the mainstream desktop environmnets, come and play on i3's jungle gym.