The only problem I have noticed with using Cronolog is that it adds two processes everytime it is used. If you have lots of virtual hosts and a cronolog for the ErrorLog & CustomLog that adds four processes per VirtualHost.
 
Edit: It seems that only on Apache 1.3 does apache create two processes for a piped logging program. It forks a shell and then runs cronolog. I'm seeing this in an Apache 1.3 server:

13311  ??  I      0:00.00 /bin/sh -c /usr/local/sbin/cronolog /usr/log
+s/httpd/%Y/%m/access_log
13314  ??  I      0:00.36 /usr/local/sbin/cronolog /usr/logs/httpd/%Y/
+%m/access_log
[download]

vs. on Apache 2.0:

29394  ??  I      0:00.04 /usr/local/sbin/cronolog /usr/logs/httpd/%Y/
+%m/access_log
[download]