I tell you a while back I obtained a cPanel server for couple reasons, 1) the demand I was having for people still wanting to use FrontPage with Extensions and 2) some people just wanted cPanel.
But I got a who new appreciation for InterWorx (SiteWorx) today trying to figure out why a customer couldn’t connect to his cPanel Addon domain. Come to find out that a Permanent (301) redirect has to be done when adding a Addon domain to get it to work correctly when publishing. (Not to mention that Google and all the other search engines will index the primary domain and the Addon domains subfolder which causes all kinds of SEO issues)
How InterWorx handles Secondary Domains is nice, really nice, it just took me messing with cPanel to fully realize this. Never getting rid of my InterWorx servers. Never I tell you!