Maths is great. I use it primarily as an EG but when I'm done patching I almost always notice I've used up all the channels Maths has to offer wishing I had more.
I really just needed an extra Envelope Generator so I was contemplating buying Contour or some other EG instead of Maths. I watched all the videos about what Maths can do, read all the reviews, but I still wasn't convinced I really needed all the extra functionality... until I got it. I've had it for over a year now and I can't imagine a modular rig without it, although it's possible to get almost everything Maths does out of other modules, but you would need several to replace Maths' functionality.
As an EG it's really handy: snappy, reactive, flexible, ... . If you send a trigger into it it acts as a AR envelope and if you send gate into it it reacts like a AD envelope. I have an Intellijel Dual ADSR next to it, which is great, but when I can I use Maths. I really like how it sounds on 'acid' or 'pluck' basslines but it's just as handy on slow settings.
As an LFO it's quite versatile too as you can modulate the attack/release times and shape them any way you want. If you turn down the attack/release times you can get a decent sounding VCO which I use to modulate (FM for example) other VCO modules.
The end of release/end of cycle outputs get more use than I thought they would. I've used these outputs to make a sequence swing (by delaying a clock-signal) or to simply reset all my eurorack sequencers at once.
I've used the OR/SUM/INV outputs to sidechain a VCA to a kick or simply to add CV from 2 (or more) sequences.
If you're still wondering... Yes, Maths is definitely worth it.