Larry,
The Pipedreams I am familiar with are the big ones as I have a friend who owns them. These speakers are far from perfect though. He is having to re-engineer everything from the crossovers to the electronics in the subs! I think many audiophiles who gush over the Pipedreams are only hearing their positives. There are many little things amiss with these speakers that need to be addressed before I could declare them a complete and successful design.
Regarding GR Research's crossover design and their inherent dispersion characteristics; I suggest that you contact Danny Richie himself. He is NOT secretive about his design decisions or how he arrived at his topology choices. As far as I'm concerned Danny waaaaay above most other high end speaker designers.