I, too, recently hived a large swarm. Because of it's unusual size, I suspect it is a "prime" swarm - the kind with the original mated queen from some hive. This is often described in the literature - "Large (prime) swarms" - tend to be basketball sized and up. Secondary, or after-swarms, are more commonly football/soccer ball sized, to occasionally as small as a softball - these usually have a virgin queen.
The one I caught was about the size of a beach ball, and fairly well filled two 10 frame mediums with about half comb/half bare frames. While the swarm was less than 20' from my hives, I haven't been able to find any hatched queen cells or notice any reduced activity among my hives - apparently a gift from some other nearby hive? Another hint - I run small cell frames ( bees are a bit on the small side), and the swarm bees are noticeably larger. It was almost like they were seeking me out - attracted to my Fine" operation...
Good luck to all with catching swarms - instant increase!