Looking at an individual entry from the RSS feed, you get the entire tweet, the time, and the Url of the tweet. e.g.
BadAstronomer: @neito No, Randi's alive & still annoying frauds. A Fark link made it look like he'd shuffled off this mortal coil: http://is.gd/4fZBo
Tuesday, 13 October 2009 8:44 AM
BadAstronomer: @neito No, Randi's alive & still annoying frauds. A Fark link made it look like he'd shuffled off this mortal coil: http://is.gd/4fZBo
Note that any links within the tweet don't retain their linked nature. Same with any "@replies" and #hashtags.
In short, if there is an ability within the API to have the original tweet retain it's original links, then that's certainly worth the extra effort, I think, because otherwise you either forfeit the hyperlinked richness of the original tweet, or you have to parse and relink links, replies and hashtags which could be onerous.
I guess it depends on the sort of tweets your company will be making. If they are plain tweets with no links, then I can't see an advantage to using the API. If, however, they expect to use the normal link-grammar of Twitter, I'd be using the API.