I haven't tried most of these, though I used to use ratpoison and agree that it's quite pleasant when you have a small monitor or laptop screen and don't need to run something like the gimp. Very good choice if you spend a lot of your time in emacs (and don't often use transpose-chars -- okay you can always rebind -- anything's going to collide with some emacs keybinding unless it used the windows key as a modifier).
I've started to use acme to replace much of my xterm activity (at least non-root -- is there a simple way to use acme with sudo -e in plan 9 port?). Does that count as a tiling window manager? This is the issue keeping me from trying out tiling wms anymore or bothering to use the new tiling style command added to OpenBSD's cwm: acme makes tiling and automatic sizing work really well but only because it combines with other features in predictable, designed ways. e.g. I right click on a directory name and a sub-window opens with my mouse in it giving it focus and sized just right for the number of files in that directory. Also it works well with proportional fonts unlike most Unix programs I use other than the big bloated ones that have adopted the Macintosh/Windows UI. Proportional fonts help avoid screen real estate waste, and just plain look better IMO.
What window configuration choices can a general purpose X wm make for you to behave really well with whatever random application makes a window in it? My experience with ratpoison was that it was a good way to run everything full screen without messing with maximize buttons or losing space to window decorations. Maybe occasionally I got good use of the split screen between two applications feature. But even that was kind of awkward, never mind anything more complicated. I could imagine using stumpwm and customizing it with Lisp for the applications I use, maybe in combination with applications you can communicate with to adjust what's in their windows. e.g. "hey xterm, you're going up in the top right corner for now and I want you to use tiny text until you get back to a reasonably sized window again." That might be fun and eventually give me something good. But I find it hard to imagine someone else has done just what I would want with their automatic sizing behaviour other than for simple splits of the screen or making everything run full screen.
Now I use cwm and for the things I always run I use geometry command line arguments to place them (bound to key presses) or in the case of emacs some internal geometry related customization to put two non-overlapping frames on the screen, the bigger left one in mono font, the smaller right one in proportional font, for reading documentation, etc. I have to figure something out for when I undock my laptop though, cause this setup only works well with a bigger monitor.