Hi Russ
I now a lot of people mention they like products from Klipsch. I did notice that the speakers on this link have a maximum burst power of 500 watts, whereas the z5500's are 505 RMS watts. I understand that RMS is really the best unit of measurement to go by. Max burst power sounds like it must be their idea of peak power. In reading between the lines here it appears to me the z5500's then have a lot more constant power that can be used.
Only listening though will tell you if it's for you or not.
Best
Scott