This post just reflects my findings for both WP Super cache and W3 total cache plugin for wordpress site caching.
There has been much debate on this topic on the internet and as covered in the comments here: http://blog.tigertech.net/posts/use-wp-super-cache/
We have few different wordpress sites for some of our content. None of these site use CDN or get very high traffic. But we used Apache Benchmark to simulate large loads and tested which plugin worked for us and surprisingly both plugins cater to different use case scenarios as discussed below.
For post based sites, which are mostly the largest installations for the wordpress – W3 Total cache fairs very good.
Apache Benchmark test with 10000 requests and 500 concurrency barely breaks a sweat on a low powered VPS(1 vcpu, 512 MB RAM).
However, for a site which is totally using “pages” in wordpress and not “posts”, we could not get W3 total cache to perform very well. Even with 1000 requests at 100 concurrency would take cpu used by apache forks to 20-30% and system load would go up in double digits.
So for “page” based site, we tested WP super cache and it really faired very well. The load barely moved when hit with 10000 requests with 500 concurrency.
Both the servers have apache2 as front end web server.
So, tldr: W3 Total cache is better for most scenarios(and hence has higher user ratings). But in case you are running just a page based wordpress site, WP Super cache is your answer.