I am impressed by this site's use of Bootstrap. Most Bootstrap sites look like exact clones of the example templates with some colors swapped. The Bootstrap origin on this site is obvious yet not tired.
All they did was add a background and position one element yet it looks unique. I think the key thing was that they avoided the Bootstrap's black navigation bar.
IMO what matters most is Bootstrap was used well. They took the purpose of Bootstrap (CSS/HTML Framework and well designed common elements) and then used that alongside their own understanding of how their site should be fit for the purpose.
So many people take Bootstrap as an excuse to not give a single thought to the usability of their site. It's a shame really, Bootstrap is a great tool but inevitably the people that rely on it are relying on it because they have no clue, so they butcher it.
All they did was add a background and position one element yet it looks unique. I think the key thing was that they avoided the Bootstrap's black navigation bar.