Are first order crossovers best?

I started a thread on this a while back which turned into a sometimes heated and very informative discussion. I'm no computer whiz so I don't know how to locate the thread and provide you with the link. But I bet someone, perhaps yourself Blindjim, can locate it and I would recommend you do. I heard from everybody from Jeff Joseph of Joseph Audio (who uses very steep 4 order filters) to the guy from Green Mountain Audio (can't remember his name but a proponent of first order designs). Also, check out Richard Hardesty's "Audio Perfectionist". He adheres to the first order mantra. After much reading and reflection I came to the conclusion that you need to design the crossover to work with the drivers you have selected and the overall design. This is much more important than phase coherence. Can even the best drivers operate far outside their natural frequency response limits in a 6db slope design--I have my doubts. Should all drivers be shut down radically so they operate within a fairly narrow range of frequencies--I don't think so either. I am of the opinion that the dogmatic approach (i.e. must use first order, must use 4th order) doesn't make a lot of sense. Rather, the crossover should be tailored and tuned specifically to complement other aspects of the design (intended use, drivers, bass loading, etc.). Of course I'm no expert and you should read some of the literature out there for yourself to form an opinion.