Sometimes, I'd even go as far as to say, most of the times, coloration you get from a plugin or hardware module, is a side effect of distortion. There are different levels of distortion, however. Some types are good, others are bad.
When you have access to decent source material, an exciter is useless and unwanted. Exciters are usually band-aids for material that is sub-par. You generally use it when something is beyong the normal means of EQ and you need to breathe life into it. 99.99% of the time you shouldn't need it. I can't remember last time I looked at an exciter. You see them more in live sound rigs where they're used as a quick way to add "air" to the sound.
You can kill a mosquito with a shotgun but you'll end up doing more harm than good in the end. An exciter is usually too much for anything and the actual side effects are not worth the remedy.