The benefit to the Cornwall is you can drive it with one watt! The Pass amps wouldn't even break a sweat. That being said, XA amps like to be driven hard. The harder you drive a Class A amp, the cooler (although only slightly) it runs. So with such an efficient speaker, the amp might run a pinch hotter.
I will say this, people tend to either love or hate the horn sound. My Father has Klipsch speakers and he wouldn't have anything else. Me? I'm not a huge fan. But its personal opinion.
Depending on your budget, there might be some other options to consider. You have a terrific amp by the way!
Mike