The whole idea behind the RT is the fact that when a user is on your site and they decide to use the plugin to submit your article to Twitter, then they will be updating their Twitter status with a RT directed at your username followed by the post title...
Imagine if I were on your site and I just tweeted one of your articles (hypothetically)... It might look something like this:
RT @rfischmann: This is the title of a great post for you to[...] http://e7t.us/12345
That's the whole reason for the RT, simply so that they will be ReTweeting your article.
Either way would work I suppose... I'll add an option to be able to use whichever floats your train in a future update.