Well, you can estimate the impact. There are many lists in our objects. A linked list and this is at least one extra pointer per item. That's four bytes (using pointer compression). We currently have 45million labels, all in lists. That's already 171MB of memory just for pointers. Could easily be three times as much with all the other list-based items. The true overhead would be *much* bigger if the LinkedList implementation uses some kind of auxiliary objects for nodes internally, which seems quite likely. It might be GBs of RAM we are talking about here.