Summary:
Not too many people are aware of the "professional" sound equipment. In many cases, audiophiles simply do not like the sound of them. An electronic crossoveris actually a remarkably simple circuit with some resistors, capacitors, and opamps. Sound quality gain by spending a lot of money on a more expensive unit is minor compared to something like a speaker.
First thing one notices with pro equipment is that they're built tough simply because they have to survive harsh environment created by outdoor use and so forth.
Looking inside, one notices good quality thin film resistors and Neutrik connectors all around. However, they cut corners in casing (good quality, but not precision quality), knobs (cheap plastic stuff), and
power supply. The only thing that annoys me is the fact that they cut corners with the power supply. 470uF caps? Come on!
I also have an Ashly (another pro equipment manufacturer) XR-1001. In that one, they did a fine job with power supply, casing, etc, but used 5% resistors throughout and used cheaper connectors. And they're not even consistent between channels.
As an audiophile, I am keeping the dbx one because it has simpler circuit and uses better opamps. Ashly's built quality is much better, but the extra features
are not good for the audio quality. Don't get me wrong. They both sound heck of a lot better than when I used the passive crossovers in my speakers.
Ashly is definitely better for the rugged professional life not only because of the better casing, but because the circuit is very modular and easy to repair. One can't have a band tour cut short by a broken crossover
that can't be fixed easily. All in all, both get 4 points. Ashly for pros and dbx for audiophiles.