Are first order crossovers best?

I'm only guessing here. Perhaps because some cables purport to maintain absolute phase better than others. Only single driver and 1st order cross-over speakers maintain absolute phase. Of course the skeptic might say that sellers feel the need to provide a reason for all the cable options and a means to qualify their suggestions.

Unsound you're partly correct on the 1st order=correct phase. Until recently I thought all 1st order crossover speakers maintained correct phase.To my dismay there's a couple of imposters in the group.Sonus Fabers and some Dynaudio speakers have their tweeters and midrange drivers wired in/out of phase or the bass drivers are wired in/out of phase.The drivers in these speakers aren't all wired in positive polarity together.

I think that's one of those things that boil down to a matter of taste. Most people in audio are trying to build a system that serves their music, and gets out of the way. Some people are disturbed by phase errors or certain types of distortion, and some consider these acceptable trade-offs.

I personally prefer time and phase coherent speakers, although I have none in-house right now. I was raised on Vandersteens, and these kind of speakers just seem to serve the music better over the long haul. Of course there are only a few companies making this kind of speaker, now that Meadowlark is gone. The parameters that are needed to make a first-order speaker go are more limiting to a designer than than say fourth-order ones.