I've never used Zapier, but I have to admit that this article in conjunction with my frustrations with IFTTT lately have me looking at it.
I actually use both, although it can get confusing. Not all apps are on both services. In general I prefer Zapier.
Is that because it's easier to set up or because of capabilities? I'm seriously considering a switch or build of custom solutions.
I'd say the capabilities - I think you can do more although I haven't looked at the latest updates to IFTTT and their applets. I've also played with this some: https://stamplay.com/