I have handed the CMS keys for Ghost to non-technical people with good results. There's no doubt that it's more limited (especially in terms of plugin ecosystem) than WP, but that lack feels liberating. No need to agonize over which contact form plugin is the right one to go with, etc. And Ghost is certainly snappy [0].

[0]: http://blog.appdynamics.com/nodejs/an-example-of-how-node-js...

No idea about Ghost. I found Jekyll to be too limited for client work - but it's been a good 18 months since I used it.