We are using WP 4.0 and the layout should be in the home page. I’ll also drop it in another page for you to test with….here it is – http://www.thehandmadehome.net/masonry/
What kind of load times are you seeing? It’s loading pretty quickly for me…so I’m wondering if there is a caching issue as well. Have you heard of any issues with WP Super Cache with this plugin?