Andy,
As Bryan noted, I have line arrays triamplied by 3 Panny's (using digital in on the 3 amps) the system uses a DEQX for crossover and speaker/ room correction. A audio guy in Cary had a set of Orions, and now more like Phoenix'es that he uses a modified Linkwitz analog crossover with. There is a also a guy on the DEQX group that has a pair of Orions that he uses the DEQX with in place of the linkwitz crossover, but you have to be a DEQX owner to get on that group and he doesn't live in the Raleigh area.
If you're going to use the analog line level Linkwitz crossover then there is no big advantage to using the pannies except for remote volume control and low cost, since you'd be using line level inputs, and there might be some better options. Where the pannies work best is is when fed directly with digital in.
If you're in/close to the Raleigh area and want to listen to my system and discuss options for what you want to do just PM me, it might take a while for me to respond though.
Roger