Too small of a community, and quite unknown in web server world. One example of the problem you may have is if you write Pike code for Caudium, and your hosting company doesn't support Pike, and you don't have root access to your server. Of course, it is possible to compile Pike on your account and run Caudium without the superuser privileges.
RIS (Roxen Internet Software) owns Pike, but this is likely to change in the not-so-distant future.
Needs more testing for exotic modules or modules we don't use often. Example of such modules include htaccess support.
Too little documentation. One example is the lack of documentation about FastCGI support.
CGI performance on busy CGI based sites was lackluster -- no one will take the time to rewrite CGIs. This seems to be somewhat resolved with Pike 7.2/Caudium 1.2.
It is sometimes impossible to get some features when you are a normal user because configuration is only accessible with the CIF. (Configuration InterFace). And the CIF. is accessible only by the admin (this is being taken care of in the development series of the server). Here is list of day to day problems submitted by Chris Davies:
Webmasters like to use mod_rewrite in the .htaccess files to protect their sites from leeching, etc. Yes, there is referrerdeny and browserdeny, but these are accessible to the System Administrator, not the casual web user. On Apache, one can easily specify rules on a per directory basis. This isn't easy in Caudium, however, it is rare that someone would have more than two or three different conditions.
Now, for people that are running their own server, many of these issues disappear. Administration and adding servers is much easier. I'm not sure I agree with the templates, but perhaps an Apache Template could be tweaking beyond that to the System Administrator. In most cases, Apache has SSI turned on for shtml files -- getting the exec command enabled to mimic this in Caudium is not a task for the beginner. The maze of options to find that one setting will certainly frustrate anyone getting started.
A graphical interface is not always the best. To create a virtual server with Apache, you have to copy and paste five lines. If you use the Caudium Interface it will take you more than one minute. And if you want to change Caudium text file directly, you will have to write sed script.