Ranked in these QuestionsQuestion Ranking
Pro Tags instead of workspaces
With awesome, clients are organized with tags: one client can be on more than one tag, and multiple tags can be displayed at the same time.
Pro Low latency
Awesome was the first window manager to be ported to use the asynchronous XCB library instead of XLib, making it much more responsive than most other window managers.
Pro Highly configurable
Awesome is highly configurable, allowing the user to change anything they see fit in order to make the WM work for them and their workflow.
Pro Fully extensible with Lua
Pro Keyboard friendly
Awesome is really keyboard friendly and you can do almost anything with keyboard shortcuts.
Pro Some mouse tiling support
You can rearrange and re-size [some] panels via the mouse.
Pro Good default configuration
By default, you'll have a status bar (hidden in some modes), an application launcher, automatic fullscreen, manual fullscreen shortcut, etc.
Pro Single window, multi-workspace support
The user can have each window visible on one, multiple, or no workspace. You can also temporarily include another workspace in the current one.
Awesome always works as it should: it is very stable and reliable.
Pro Any window can be full screen
Select the window. Hold ALT+SHIFT and press SPACE until the window takes up the entire screen.
Pro Xinerama support
Awesome has real multi-head support via XRandR/Xinerama, with per-screen desktops.
Pro Easy module for useless gaps
Lain module makes useless gaps easy.
Con You should have some skills to configure it
Awesome, like most window managers, is targeted at advanced users. Though is has sane defaults and easy to read documentation, it is still a far jump from the more common graphical UIs found in computing.
Con Difficult to google for solutions to problems
Awesome is a very common word, making searches for solutions to problems using Google very time-consuming as a lot of chaff has to be sifted through.
Con Doesn't have tabbed containers
There is no option to have tabbed containers in awesome window manager.
Con Some programs don't cooperate well with tiling window managers
The user can usually work around this, but it can be quite annoying at the same time.
Con Concept of layout sometimes does not fit what you want
The concept of layout sometimes does not fit what you want, for example, if you like the concept of layouts in tmux or in i3 - it works differently here.
Con Regular API breakage
Results in many of the scripts for awesome to be found online end up being outdated.
Con Configuration uses Lua (Programming Language)
It is time-consuming to make changes to configuration. Though Lua is a good language, a plain text file to configure things would seem to be a better approach.