yeah, by the time I've remembered to open Google Now and slide up the cards I would very likely have realized what I might have forgotten.
For me, it's only showing the local weather, which I can see out my office window. And besides, this is CA. Forecast for the rest of the year is Sunny and warm.
I suspect that using the very simplified iOS notifications would probably get irritating quickly. Sample size of 1 but my iOS notifications tray is always a disaster compared to my Android, I think because it doesn't coalesce notifications the same way so you commonly have 5+ notifications for a single app.