When I was at the University of Wisconsin I occasionally found my way up to the library's Cutter Collection. While the Library shifted to using LCC in the 70s they kept a set of books organized by Cutter's system. In practice, I often ran into others from the history and history of science departments browsing through the stacks. You can find guidance docs about the collection from the history department. It was neat to see these older books organized together and set aside to be browsed as a collection.
So, I'm curious to know a bit about the places that are still using Cutter. Are they doing so because of the amount of work that it would take to change? Are they doing so because it is what people know? Or are their other arguments for organizing books this way?