I mean, you’ve said it here yourself. If what you mean by “the lowest common denominator” is, "Apple Notes is the most basic note taking app,” then I would agree with you. (That is both question and statement.)
So, yea, to me Agenda capitalizes on what Notes doesn’t do and knocks it out of the park, far and away. The latency I described wasn’t huge, and I have to also consider that I’m using a bluetooth keyboard between two MacBook Pros, one having smaller RAM than the other. This might add to the latency, but it’s not a serious headache for me. Like @drewmccormack and @mekentosj mentioned, it’s about knowing your device and having a balance.
I did a quick search, and I didn’t find too much in the way of hard-core comparative analysis between Notes and Agenda. The only information I found was people talking about needing more integration between them, which, to me, was a kind of additive comparison. And I’d like to point out to you, another thing from here in the Agenda community, which you commented on:
It’s a great post, and I missed it, frankly. So today was my first time seeing it. In response, my resolve for the Things 3 issue is that I don’t need it, since Agenda already integrates all Reminders lists, not to mention Agenda’s own built-in list.
As far as Notes, it’s a simple share to Agenda (the iOS share menu is pretty straightforward when importing into a preexisting or new note in Agenda). Otherwise, it’s a simple copy/paste function. I think thats as good as it gets (unless the DMA coming to the EU this month has any effect on this issue — sidebar).