Hey joesh,
I wanted to share my opinion on Stages vs Maths, since that's a decision I also made not that long ago.
I went with Stages and it's a lovely module. however I also have an additional Analog function Generator in my Rack. which I'd be tempted to say is like one half of Maths, but that's not the case (I also have shades from MI for attenuverters offsets and mixing, that plus a single function Generator is a lot more like half a maths and suddenly takes up 12HP). One difference between the Function Generator that is hard to Grasp and describe for me is the immediacy. Stages is digital at heart and if you want to clock it or something it will take a few clocks to settle into a steady rhythm sometimes, sometimes there's artefacts, etc., there's a few times I've found myself wishing it would be more "playable" more "immediate". However I think that the possibilities with that module are almost endless but I recon it's a very different mindset to the Rampage, Maths, Doepfer A-171-2, Falistri, Delta-V and alike. It's a means to an End, very versatile but at the same time intentionally limited and focused. It's weird to describe but it really drools with the Mutable Instruments way of doing stuff.
I love it, but you might not.
All the Best
Chris