For sure, different travel patterns. And yet, both close gaps in the existing network. Yonge North will connect the HWy 7 corridor to the Yonge subway stops. Finch extension will create a northern crosstown route and connect to multiple N-S routes.Want to elaborate on this? As far as I can see, they target two totally different trip types and travel patterns.
Yonge North will have a much higher ridership, but a much higher per-km cost as well.
Anyway, that's a mostly academic debate. Yonge North is very likely to happen sooner as it is more popular, and I'm perfectly fine with that.