The dealer is a tool! Anyone who tells you that it'll be too loud or sound like anything other than a well-built V8 are full of it!
My cars sounds smooth, low and mean. Its not too loud or obnoxious by any means. All the resonators are doing is restricting your airflow and muffling the sound so the older set that they were catering to generally wouldn't want to hear the exhaust....not to mention adding unnecessary weight. Delete the resonators, straighten the pipes, replace with 2.25", replace OEM mufflers with high flow Magnaflows, Megans, etc... and consider replacing the cats up front with hi-flowing ones. You'll notice a huge improvement in sound, a noticeable improvement in HP and better mpg just by replacing the mufflers/tips and removing the resonators alone.
If I don't like the sound with out the resonators, how hard is it to add them after? The dealer was really stressing on the resonators, was making fun of other cars that didn't have any.