If you have a low traffic site like mine, WP Super Cache is a clear winner. It is very easy to set up and maintain.
W3 Total Cache, on the other hand, is very difficult to set up and doubly difficult to set up if you use MaxCDN. These two tools are probably overkill for light traffic sites and might actually slow down your site.
Furthermore, in order to gain speed from W3 Total Cache, you will probably need to spend hours fiddling with the settings. If you want to add a CDN, plan on even more hours, unless, of course, you already know how to do it. W3 Total Cache will configure the plugin for you for around $150. Not a bad price if your time is worth anything. Since I did not buy the service, I can’t say whether it would help or not. One final word on W3 Total Cache: The plugin has not been updated in over a year and I suspect that there are some bugs or incompatibilities with WordPress 3.4.2. That might explain why I had such a difficult time getting the configuration set so I could get a speed improvement. The developer, Frederick Townes, claims there is a new version coming any day. I can’t wait to try it out.