After I posted that, I read the “Complete Idiot’s Guide” and got a better idea of what it can do and how it works.
It’s very modal in its feature set, unlike the Tyme Sefari which feels sort of patch programmable by comparison. But then it also has several features TS doesn’t, like the slicing.
Ultimately I decided to go with the ER-301 and roll with whatever features I need for the patch at hand.