Thanks, Wayne! The extra attenuation for the 8R DE250 sounds smart. I wouldn't be averse to using a 100w L-pad for some flexibility...My tendency would be to use lower wattage on the resistors since my "big" amps (SE 845) are nowhere near 100w, but I think I'll follow your advice. I may be loaning these to a friend who thinks he needs to spend a lot to get good speakers (Stereophile reader!). Knowing they could handle even a big SS amp would provide peace of mind.
Is your crossover board useable with the large inductor values needed for the 16R woofer? To make matters worse, I like the Erse inductors for these large mH values. The Erse are nice for mounting to a free-form board, but maybe not to your PCB...