uuh.... X..... last i've checked, with most online RPG's (or at least those of late), you have to have a valid CD key from the purchased product on your game account (or a main account when it comes to games such as City of Heroes/Villains, Auto Assault, Lineage 1/2, etc...). they have absolutely no way of knowing whether or not you purchased the DVD version. Just about all you ever really get with the DVD versions of games is something that didn't come with the CD version, but doesn't really give you an advantage either.
I'd say it's kinda up in the air. i mean you physically purchased a legal copy of the game, you have a CD key...... though we know how greedy some companies can get.
and as it's been said...... if you do download a DVD Version..... make sure it's the official discs, not a cracked version of it.