5TB is fine, good amount of traffic. 500GB od storage also is great. The only touble is that you NEVER come to use that much simply because the Dreamhost service it too bad for it. Outages, slowdows and short drops are common on WWW service so you never use up your bandwidth.
I thought that setting up Private Server would make the situation better, but the reality (I already have PS) is the exact opposite. Bad service went into no service at all. My PS does NOT work at all, all my sites are down all the time. I reboot, the works for a while (a few minutes) at lightning speed and the everything stops. No WWW at all.
To use all 500 GB of space, you would need good upload speed. This is another problem at Dreamhost - constant FTP crisis. You start uploading, it starts up very fast and in a whiole it slows down to crawl. Dreamhost probably uses some kind of bandwidth tthrottling to prevent people from moving around too much data by FTP.
So - for just a very simple personal site, go do Dreamhost's shared hosting. The setup is fast, domain registration is done in minutes, the control panel is near perfect.
But - if you want a professional site - forget Dreamhost!
I did make this mistake, I built over a dozen of profi sites, spent months working 20 hours per day and now I'm one very very unhappy client of Dreamhost.
....I just rebooted my server again and again it is at lightning speed. A few minutes from now it will be dead again.....