Agreed on previous comments - a super tweeter will not add sparkle. Most of these drivers can and will reproduce frequencies up to 20khz and beyond. You will really not "hear" anything a super tweeter would potentially add, unless you have a very damped room (with lots of sound absorption).
It's amazing that many people do not realize that much of the perceived high frequencies are actually coming from BOTH the midrange and tweeter. There is a huge amount of high frequency detail that comes from midrange drivers as low as 3,000 to 5,000 hz. The quality of the midrange can definitely affect how you feel about the "sweetness" of the highs. I have experienced this by comparing a coated paper midwoofer with a coated magnesium midwoofer - in the exact same cabinet with the same tweeter. Crossover at that point was 3khz. So, if you love the sparkle and sweetness of the totems or Gallo, it is likely that the Revel sound more "sterile" or "flat" to your ears.
