First of all, let me say that my current host is DreamHost & they don’t use cPanelX. And from my personal experience I know if you want to setup your website in their web panel from a cPanel exported dump file, it may become a little bit tiresome. Especially, if you are a newbie, then you may face some trouble putting the files in proper place in the server with correct structure. Besides, you have to create a new MySQL database & import your existing database there. And that may require some phpMyAdmin knowledge.
But the good thing is that you don’t have to worry about these things from now on. DreamHost have added new cPanel import feature to web panel. I received their newsletter yesterday. Now you can just give your cPanel login information & they will import the site from existing hosting company & set it up in your DreamHost web panel. You don’t have to do anything except updating your domain’s nameserver info. And if you don’t want to supply your cPanel login info, you can just export the zipped file from cPanel & DreamHost will take care of setting it up for you.
By the way, as a current customer I am happy with DreamHost. They have pretty good uptime. Seldom their server goes down. Only problem is that when it goes down, they take a lot of time to recover it. But at least we can see the status update from DreamHost status blog.