Direct Admin is less buggy than Cpanel. The more features you have to more thing developers have to fix.
I heard performance wise.. DA is a lot faster than CPanel (out of the box context) If you know how to configure Cpanel and tune it properly.. Cpanel could be fast or faster. Well it is all depends on your admin's hand.
Fantastico is not part of Cpanel - Just an add on.. nicely fit into Cpanel environment and cost you more $$$. But it helps the hassle of downloading and chmoding for newbies.
DA is also has the same. called installatron.. You have to purchase it separately like fantastico (own box - not dedicated)
I think you can find more hosts using Cpanel nowadays.. So if you screwed your box.. you can easily find information or help.
One thing that i don't like about Cpanel that it is bind to your OS.. you could not uninstall it.. If you try to remove it.. the box might refuse to work and you have to reload a fresh OS.
To me it is a matter of preference.. Cpanel more buggy but popular.. DA is catching up though...
Sometimes too much of a good thing (like cpanel) give you a lot of headache.. lol
esp in explaining part (to your customer)..Thank god they have this thing called "Flash Tutorial"
