I didn't see this thread until now - whan a casual search revealed it.
(Sorry about the long post that now follows).
I have been using the Beringer DCX2496 in my gear. Bearing in mind that this is a $250 cheapo unit, it does offer some remarkable abilities. It does, however, have its limitations, but IMO it's weak points can (mostly) be avoided.
IMO, electronic crossovers - when done right - are almost always audibly superior to passive networks. Unfortunately, this always means carefully optimized filter transfer characteristics, matched to the actual frequency response, rolloff and phase characteristics etc of the actual driver units in your actual box. Measuring equipment and some means of crossover optimization is a must. The ability to build your own electronics is another must.
(Standard generic commercially available electronic dividing networks (which usually have LR24 slopes) will in my experience seldom give correct transfer functions with (most) actual speaker units. A commmon occurance for folks auditioning (the same) speaker systems with active or traditional passive crossovers is to blame the audible differences on the electronics themselves rather than the changes that were introduced into the system by the different transfer functions.)The Behringer DCX presents an attractive way for obtaining an electronic crossover optimized to your actual speakers without having to construct and build your own electronics. However, this convinience comes at a price. IMO the sound of properly built analog electronic crossovers are superior to the Behringer - even if the transfer characteristics are quite identical.
But I will not write off the Behringer. The unit is cheap and flexible. I use it for fast prototyping. When a design of mine becomes a keeper, I make a decent analog filter for it - passive or (mostly) electronic.
If you wish to use the Behringer as a more permanent fixture in your setup, keep this in mind:
1. The Behringer is noisy. There is no master volume control. With power amps of normal sensitivity/gain and efficient speakers, the hiss level will IMO be objectionable if you not introduce a volume control between the Behringer and your power amps. Keep in mind that for a 3-way stereo system, this has to be a 6-channel close tracking volume control - not easy to implement. There exists some 6-channel electronic volume controls as DIY kits, but they easily cost alomst the same as the Behringer unit.
2. The Behringer can correct for large differences in sensitivity between units - for example 90 dB/W for a bass unit compared to a 112 db/W horn driver. But it uses a lot of DSP processing power to do that, and the sound quality suffers. Sensitivity corrections can just as easily be accomplished with passive resistors (L-pads) directly on the speakers - with audibly better results.
3. The Behringer is very flexible, and has a multitude of adjustments. With it, you can accomplish just about any transfer function. But for good results, it is totally necessary to measure the speaker individually - both without and with filtering. Measuring equipment is a must. I also doubt that it is really possible to get consistent, good results without a crossover optimization package. I use lspCAD.
The Behringer is a complex tool in a cheap package. The low price can fool us into believing that it is a unit that is simple to implement and use. It is not. But used correctly, I would have no reservation to recommend it.