I'm using the webserver for quite a while in business critical environments and it did not fail me. I like the unique security features this webserver offers(Anti-XSS/CSRF/SQLi), but also the simplicity in how it runs, just fast.
I call the "RandomHeader" option for TLS revolutionary and really clever, because it hinders guessing pages visited by size of response, since it adds a random header size to the answer.
Whenever I had difficult problems to resolve, the developer helped out, nice to see a developer being so helpful and enthusiastic.
For me, theres only one webserver to pick, Hiawatha.