Strengths: Steep 24db xover slopes, variable xover frequency and subsonic filter based on resistor values.
Weaknesses: xover frequencies are a pain to change due to the resistors, unit is prone to noise.
Summary: I have owned my 2 24xs's for a few years (one is about 4 years old, the other must be over 5 years). I like the ability to EXACTLY select the crossover frequency (and subsonic filter) by changing resistor values in the DIP connectors, though it is a bit tedious to do so. The 24xs also has a "SWAT" feature which alters the phasing of the high or low pass outputs (selectable); this feature is useful if you notice a volume drop right around the crossover frequency (for eg. where your mids attenuate and your tweeters take over).
One thing I don't like about the 24xs is it is noise-prone. I usually seem to have some problem with noise when installing it or changing my system, and have to fiddle with the ground selector (yet another switch inside the unit).
In summary, a great crossover, if you want to deal with a little complexity.
Similar Products Used: Audio Control EQX, Alpine 3402, Hifonics Plato