I use this unit mainly for rhodes piano, from gentle lead drives to huge broken fuzz distortion, and for synths to add a bit of grit when needed.
I've searched for years for the right fuzz for my rhodes tones, and after about 3 other very good candidates, the Apocalypse has secured its position in this role.
The build quality is excellent. It feels sturdy and chunky, all the knobs feel tightly secured and are a joy to twist. The range of tones you can pull out of this is rather ridiculous. The fact that you have 5 modes with an equalizer makes this one of the most versatile pedals out there in its category. Guitar players can surely pull out tones for days and for producers this is a great unit for giving your artists a tool that will most certainly cater to their distortion needs.
The only downside is that it's pretty pricey, but considering the build quality and its superb versatility, you're essentially easily getting 5 pedals in one box. So ultimately the price is relative to your needs.
From a design perspective I'd love to have an additional bias/starvation knob that could push the sound even further into oblivion or a breaking point. But you more or less get that already with the existing tones.