I think we owe Jenkins a TON of credit for being a free solution that has a lot of great traction.
I'm used to seeing pages of checkboxes and can't stand how obscure some of the configuration is, but mostly I wanted to write something that could handle configuration differences between hundreds of projects, so that is why there are things like Snippets in Vespene.
Plus, I wanted to make something that was a little better for ops use cases (so people don't also have to go pick up something like Rundeck), so that's why there are things like the SSH integration and http://docs.vespene.io/launch_questions.html
It's more about capabilities and future capabilities than the frustrations IMHO.
Though I do have a bunch of friends who are frustrated with plugin compatibility, plugin hunting (we're doing more of a "batteries included" approach like I ran with ansible - just with much less modules), and stuff like that.
I was also able to add in some stuff like container build isolation really easily, and that's all included stock.
